Condensing boiler temperature setting advice But to condense that water vapor, the RETURN water temp to the boiler has to be about 135°F or below. Viessmann boilers, for example, benefit from weather compensation technology. Aug 15, 2025 · Find the ideal boiler temperature for central heating. This advice does not apply to regular or system boiler installations In this article, we’ll explain how boiler temperature settings work for the main types of domestic boiler in the UK. I have also seen recommendations anywhere from 165-180 as a typical setting. An outdoor temp of -15C (5F) or lower defaults to the max supply temp setting. The boiler usually runs at 160-180 degrees and there is a mixing loop that mixes some of the return water back with the supply to feed the radiant zones. Learn what the recommended temperatures are for boilers and water tanks. eg: If at at the current outdoor temp the curve calls for 117F water (in either supply or return control mode), with parameter L set to 4F the boiler will Setting your flow temperature to 50 degrees would mean a return temperature of about 30 degrees so your boiler would be in condensing mode continually - which is a good thing but you might find there is just not enough heat at the radiators to warm the room. how weather compensation and open therm save energy. 1 While condensing boilers do have a higher upfront cost, proper system design and installation can deliver energy savings that make it worthwhile. Understand combi boiler flow adjustment for comfort and savings. Properly configuring these settings can improve efficiency and reduce energy costs. Traditionally, boilers were set to high temperatures (often above 80°C or 176°F) to ensure rapid heating and compensate for potential heat loss. At 110F returning water it'll be in the mid-90s, and below 100F it'll be in the high 90s. This setting keeps the boiler working at peak efficiency while ensuring your home stays toasty. I have only ever had forced air and typical water tank heaters before. Optimal Settings: To make the most of a condensing boiler, set the central heating temperature at about 70°C. Most condensing boilers stop at 180F or 190F, like yours. Any higher than this and the boiler won’t enter condensing mode and be at its optimum efficiency and performance. Jan 19, 2025 · What is boiler flow temperature? Anyone with a boiler in their home needs to know about the boiler flow temperature - but, unfortunately, most people don’t. Mar 1, 2022 · Any condensing boiler is 95%+ efficient when return water temp is below 130° above 87%. With a lower outlet temperature, the water has to circulate much faster else the return temperature drops too low for the boiler, which now has to work much harder to maintain a set outlet temperature. Instead, try the methods in our guide: How to save money on heating bills. Tips for condensing combi boilers and conventional system boilers. If you have any questions regarding the settings, please call or email and we would be happy to discuss it with you. Here's how to pick the best flow temperature. Jan 18, 2019 · If the pre-purge is set to 130F the entering water temp (EWT) at the boiler will be in the condensing range at the very beginning of the burn, but it the boiler temp stabilizes at a much higher temp for the majority of the burn that will be OK. Modern condensing boilers, for instance, work more efficiently at lower flow temperatures. why the difference? Do I need to call a technician? The boiler is Solution Boilers come in all shapes and sizes. The Space Heating Temperature setting is independent of the domestic hot water setting, but if the ODR mode is enabled it shouldn't matter what you set it to, as long as the ODR mode is set to 5 for "high mass radiant". For a modern combi boiler, the radiator heating temperature should be set for a flow temperature of between 60 and 70°C. Condensing boilers are designed to extract as much heat as possible from the flue gases, But this process works best and most efficiently when the flow temperature is low, usually between 50 and 60°C Jul 22, 2025 · Optimize energy use and cut bills by setting the best boiler temperature. We show you how. Adjusting these preset temperatures may negatively impact the boiler’s efficiency. Follow simple steps to optimise heating, save energy, and ensure a comfortable hot water supply. Select settings for the boiler reset curve and flow rates to optimize the performance of the system and to ensure that the return temperatures are low enough to promote condensing (Arena 2012). Set the thermostat up to run at a constant temp, and keep lowering the K-factor until it either A condensing boiler is not a compact fluorescent lamp (CFL); you can’t simply plug it into a typical system and expect it to save energy. Regular checks and adjustments to your boiler’s temperature can contribute to optimal water heater temperature and overall home comfort. Dec 27, 2017 · If the temperature outside is in the 40s, 50s and I set the thermostat at 75 degrees, the boiler heats the house to 75 degrees. Its definitely warm when I place my hands near the baseboard. May 21, 2025 · Boilers come in all shapes and sizes, with lots of features or just a few. Lowering the heating flow temperature improves the efficiency of combi boilers. Beyond that, it would make your boiler less efficient. Explore expert boiler advice from Vaillant. For hot water, 60°C is the sweet spot, balancing efficiency and safety. Whilst heating systems have come a pretty long way in over 100 years, we’ve picked up quite a few tips and tricks to help people get the most out of their boilers and central heating systems - reducing their energy bills at the same time. If you have a condensing boiler, make sure that the return temperature is no higher than 55 degrees when heating radiators, to ensure efficient heat recovery. ' An Introduction to Condensing Boilers In the past, the industry standard for hot water boilers was based on a non-condensing boiler where the hot water return temperature to the boiler had to stay above the condensing temperature of the flue gases to prevent damage to the boiler. One is the hi limit set at 190* this is a safety in case the operating control fails. Essentially, it looks at the outside temperature, the call for heat, and the return temp (at least many do), and figures out if you could run the boiler temp lower. This is a thermostatic valve that will May 30, 2025 · Boiler flow temperature explained. With a condensing boiler condensing only starts at about 127F and lower, but with some tankless water heaters it has to be 120F or lower (due to higher excess combustion air dilution). Aug 8, 2023 · Worcester is one of the most popular boiler brands in the UK. Oct 16, 2023 · This can lead to different boiler temperature settings from one household to another. There are two primary types of boilers: conventional (or standard) boilers and condensing boilers. I live in the northeast of the US where the temps can get pretty cold. They are worthy investments for your home as they are highly efficient and cost-effective. Having a good understanding of the type of central heating boiler in your home and knowing the typical boiler temperature settings will make it easy for you to determine the best temperature for your hot water cylinder and boiler. Hot water flow temperature shouldn’t be set below 50°C (to avoid the risk of Legionnaires’ disease), nor should it exceed this for safety reasons (to avoid Apr 3, 2025 · Find out the best temperature settings for your boiler. Worcester Bosch trainer, Mike, explains to homeowners how a combi boiler's flow temperature can be reduced to help save energy. If you want to know what temperature should a condensing boiler be set at, or any kind of boiler, this guide will give you a good idea. Read on to learn the I have a vacation home with hydronic heat and a non condensing boiler. At this temperature, it seems like my house struggles to warm up. compensating controls theory. You can increase it to 65°C if you want it warmer to the touch. Condensing boilers mid 90% unless return water is over 130* then 85%. Traditional Boilers Nov 23, 2011 · I have 6 zones in a 2. This is because this is the temperature that kills legionella bacteria. Oct 16, 2025 · Want to maximise your boiler efficiency in cold weather? Our guide provides tips on how to insulate your boiler pipes, keep up with routine maintenance, and choose the right boiler for your home. With proper care, your boiler will continue to provide reliable heat and contribute to your home’s overall energy efficiency. Sep 6, 2025 · Understanding Boiler Temperature Basics Before diving into specific temperature settings, it's essential to understand the types of boilers and the factors influencing their operation. Jun 12, 2023 · Discover the optimal boiler temperature for winter comfort and efficiency. The CH set point on the boiler is 160F, which a previous post told me was too low. Operating control has two settings on and off. Any ideas? Thanks! Feb 14, 2022 · Determining the best central heating oil boiler temperature can be quite a challenge. The boiler flow temperature is the temperature of the water that leaves the boiler to go to the radiators. Learn how to adjust your boiler for cold weather and save on heating bills. The heat exchangers of condensing boilers are designed and manufactured for this. Thermostatic valves Fully open the thermostatic valves to ensure that the desired room temperature is reached in all cases. Dec 31, 2024 · Ideal Boiler Flow Temperature Settings So, what is the optimal flow temperature? Generally, your boiler’s flow temperature should be between 60°C and 70°C. Identifying the specific type of central heating boiler in your home and understanding typical temperature settings can help you determine the most suitable temperature for your boiler or hot water cylinder. Their condensing combi boilers like the Greenstar range allow convenient control of both central heating and hot water temperature. Sep 8, 2022 · In fact, condensing boilers have efficiency levels of greater than 90%; that is, little energy is wasted heating water. In the past, the industry standard for hot water boil-ers was based on a non-condensing boiler where the hot water return temperature to the boiler had to stay above the condensing temperature of the flue gases to prevent damage to the boiler. Cast iron, copper fin 80-85% made in the last 20 years. 5 story building. Customer: Hi, I have a high efficiency condensing gas boiler E75CN/E110CN and the water temperature is too cold for our shower, how do we turn up the temperature? Feb 8, 2019 · Return water temperature impact In a condensing boiler system, however, the return water temperature should be kept low in order to condense the water vapor and capture the latent heat from the boiler exhaust. Dec 12, 2013 · In order for the boiler to produce much condensate (and get full condensing efficiency out of it) the water returning water from the baseboard has to be entering the boiler at temps significantly below 125F (the very beginning of condensing. Apr 24, 2022 · What Is The Best Temperature Setting For A Hot Water Boiler? PFO Offers Superior HVAC Services, Discount Oil Deliveries, & More. The lowest possible temperature and firing rate that VIEW AND CHANGING TEMPERATURES: Setting boiler supply water temperature (See Table 2). Learn ideal settings, seasonal tips, and signs your system needs adjustment. So if the heating is not a problem, as during the summer, the flow temperature can Oct 4, 2017 · This thing is a combi-boiler. There are a lot of Baxi models – we’ve been around since 1866 – so how to set the temperature on a Baxi boiler differs from model to model. If outside is really cold, under the 20s, the furnace keeps the room at 69 degrees. Jan 17, 2025 · Higher boiler settings don’t always mean better comfort. how low temperature heating systems use less energy. Radiators are generally set up for an 11C drop so the flow temperature should be 66C. Call Us Now! May 26, 2023 · Finding the best boiler temperature is key to achieving this goal. Selecting a condensing boiler is the easiest and least consequential part of designing a condensing boiler system. Why worry about using efficient boiler settings? Well, not Feb 10, 2023 · Non-condensing boilers simply are not designed to condense, which is why we recommend keeping the return water temperature to non-condensing boilers above 140°F. Neither change the efficiency of the boiler. If water temp is set at 150° and if 70% keeps that temp it won't run at 100%. Hi HVAC advice, I am living in a place with a Navien CH-240 that drives domestic hot water and an in-floor, six-zone hydronic heating system. Best settings for a heating boiler aquastat control: Here we explain how to choose the best settings for a heating boiler aquastat - the combination control that sets boiler temperature and may also control hot water production via a tankless coil on the heating boiler. In fact, I had no idea what a boiler flow temperature was (or that it even existed) until I had an energy expert give my home a full MOT and outline everything that was making my energy bills more expensive than they should be. Allow several days for the system to stabilize after every adjustment and only change the setting for the heating curve or the room temperature on the control unit after the system had stabilized on the previous settings. Many condensing boilers with rated efficiencies in the low to mid 90% efficient range are available; however, if the control systems are not properly configured, these heaters may Mar 11, 2024 · Finding the ideal temperature for your central heating oil boiler can be tricky due to changing outside temperatures and diverse hot water demands. Combi boilers operate at their most efficient when the heating flow temperature is set to 45°C. However, modern condensing boilers are designed to operate more efficiently at lower temperatures. The pipes are copper. I usually keep the thermostat at 68F. Dec 22, 2005 · For most condensing boilers a flow temperature of 70 C will give reasonable efficiency and good heat up times for the heating. Feb 17, 2025 · If you've got a gas condensing boiler, you may not be getting the full energy savings. An important thing to consider: Setting your boiler’s temperature higher will give you hot radiators, but it could decrease its Sep 22, 2009 · Unless the boiler is designed to be condensing, you can't lower the operating temperature of the boiler too far, or you'll quickly rust out parts. You might have a room thermostat, radiator controls, a boiler thermostat and a water cylinder thermostat. Ideally this would be managed by a control system that measures actual pipe temperatures. Sep 5, 2025 · The temperature at which the water is heated significantly impacts the boiler's energy consumption. Executive Summary The combination of a gas-fired condensing boiler with baseboard convectors and an indirect water heater has become a common option for high efficiency residential space heating in cold climates. You may have to change the low boiler temperature, minimum water temperature, and possibly the high boiler temperature depending on the specific application. Ensure that your boiler is set to the best boiler temperature for efficiency and comfort, and don’t hesitate to seek professional advice when needed. The boiler temperature control knob is very basic setting displaying low to high, turn clockwise to increase, anti clockwise to decrease temperature. Jan 13, 2015 · Condensing begins at ~125F return water temp, where condensing boiler will be running 88-90% combustion efficiency. The lower lever has radiant heat and the 2 other floors have baseboard heat. . This standard does not hold true for condensing boilers as their heat exchang-ers are designed and constructed of materials that are able to withstand Jan 17, 2025 · Wondering what temperature should a boiler be set at? I've got the answer to this, whether you have a condensing boiler or a combi boiler. If you want to know what temperature should a boiler be set at, take a look at our guide to get a good idea. Your boiler settings can significantly vary from other households, May 10, 2023 · Optimize your heating system by setting the optimal boiler temperature. Understanding how to properly adjust your boiler's temperature can enhance energy efficiency and Mar 3, 2018 · We have a Navien NB-240 with the Heating set at 82C and DHW set at 45C. The photo above shows a the "HIGH" or "HI" setting on a Honeywell R8124A combination heating control, also called an Jan 3, 2018 · A lot of cast iron boilers can go up to 220F, some even 230F. In this article, we’ll explain how boiler temperature settings work for the main types of domestic boiler in the UK. Learn how to adjust it for optimal energy efficiency, better heating performance, and reduced energy bills at home. Nov 11, 2019 · The entering water temperature is the primary determinant of combustion efficiency. Discover tips, guides and articles to help you get the best out of your heating system and improve home efficiency. Jun 6, 2023 · 'Learn how to properly set up your condensing #boiler to save money on heating bills! Tips for thermostat, temperature, timer, #maintenance. For condensing boilers, install an outdoor reset control to match system output to actual load and recommend that homeowners not use a night-time temperature setback strategy. Setting the right boiler temperature is crucial for an efficient and long-lasting heating system. The fluctuating outdoor temperatures and your hot water needs mean that the boiler settings in your home may differ from the next household. Jan 1, 2024 · Boiler temperature Which One to Choose? Learn How to Adjust Your Boiler Temperature to Keep Your Home Comfortable and Energy-Efficient. How we can improve modern boiler efficiency by utilisation otherwise wasted 'latent heat'. 2 days ago · Experts from Dwellow, a leading provider of renewable heating solutions, have revealed that most people with modern condensing combi boilers are unaware of a key efficiency setting. And that's why non-condensing boilers (that leave the water vapor as steam until it leaves the exhaust stack) are 80% efficient, and condensing boilers (that condense the water vapor in the heat exchanger) are 95+% efficient. What is the optimum Wondering what is the correct temp setting for your boiler? Get expert advice to improve comfort and lower energy bills with proper HVAC guidance. Reducing the flow temperature can promote energy savings and maximise its overall efficiency. I am consistently getting the 15-16 degree differential at these settings, producing a good amount of condensate so I must be somewhere in the condensing efficiency range. Oct 10, 2022 · Finding the best boiler temperature can be difficult. The next most important factor is firing rate- keep it as low as possible. Press “Select” button for viewing following different modes on “Mode Display” Condensing boiler sales rose from 30% of the commercial boiler market in 2012 to 60% in 2016, and are expected to continue growing. This paper provides basic principles for designing a heating system utilizing condensing Feb 9, 2021 · All boilers have two temperature controls. This guide explains how to adjust your boiler for energy efficiency, cost savings, and home comfort. Aug 5, 2023 · What is the correct condensing boiler temperature setting? If you have a new condensing boiler, it’s essential to set the flow temperature correctly to take full advantage of its efficiency. Your condensing boiler should be set to generate water at a flow temperature of at least 60C (hot water tanks should store water at this temperature). Jun 18, 2020 · So, your heating contractor suggests adding an “outdoor reset control” to your boiler and hydronic heating system. When we run the hot water, the first minute or two comes out scalding hot. A combi (or combination) boiler sends hot water on demand to your radiators and hot water taps. Jul 6, 2020 · The boiler temperature was set to 180 degrees for our copper-finned baseboard heat and the indirect set at 140 to help avoid any potential for Legionella disease with a mixing valve set at 120. In fact, boilers equipped with outdoor reset can save homeowners up to 15-20% in annual May 30, 2025 · What temperature should my boiler be set at in winter? Find the ideal settings to maximise efficiency, save money, and keep your home comfortably warm. Outdoor reset control will save fuel they vary May 24, 2016 · So what happens if the replacement is a small mod-con boiler like the Peerless PureFire PF-50 (see Image #3, below)? That boiler delivers 47,000 BTU/hour at condensing temperatures and about 43,000 BTU/hour at its maximum operating temperature (assuming high-80s efficiency). The boiler remains on full time with all three heating zones open but 62-64 is as high as the temp goes. Now, I am used to having one thermostat in the home, and programming it to have different behaviors at night, morning, away Dec 31, 2017 · It's poorly stated in the manual (on p. Your preferred oil-fired boiler settings may be significantly different from the next person’s because of varying hot water requirements and fluctuating exterior temperatures. For 150 years, Vaillant heating systems have been delivering comfort for homes across the world. What is flow temperature & how does it work? Determining what temperature to set your central heating boiler at can be a challenge. Yet, if your boiler is set at the wrong temperature you won’t get the full efficiency, so what’s the best temperature for a condensing boiler? May 1, 2025 · Wondering what is the correct temp setting for your boiler? Get expert advice to improve comfort and lower energy bills with proper HVAC guidance. To heat the hot water cylinder a temperature of 65 C is usually needed and if the heating is not a problem to ensure the water can be heated easily to the usually set 55 c temperature. We compare advice from reputable sources to help you save money on energy costs and avoid unnecessary downtime. Feb 6, 2018 · And, with outdoor reset, all of these applications will provide efficient boiler operation. In this informative video, we delve into the essential temperature settings for Vaillant boilers. Fin tube doesn't really put out much heat under 120° supply. If you are operating a non-condensing boiler in a system that has a water temperature below 140°F we highly recommend that you install a cold water protection valve in the boiler water piping. Oil heating systems offer clean and environmentally-safe operation, with a lifespan that is twice as long as other fuel systems. If the boiler is operated in the real world, with a constant high temperature set point of 180F all heating season, it will very rarely condense and likely only have an efficiency in the 85% range. If you were to set it to a higher temperature, it runs the risk of scalding with the water being too hot for use. Even when we lower the DHW temp the first minute is still the same. We could easily see water temperatures as low as 80°F or as high as 160°F. Is there a maximum Generally speaking, the lower the temperature the better. What temperature should a condensing boiler be set at? Set your condensing boiler to a temperature of 60°C for the highest efficiency. Factors that help you find out the best temperature for your boiler include knowing the central heating boiler type you have in your home and the usual temperature settings. Explore Our Heating Oil Delivery Services Learn More About Our Home Heating Services What Is The Best Boiler May 30, 2025 · Boiler settings play a crucial role in the performance and efficiency of your heating system, but adjusting them can be confusing for homeowners. Would this be a good investment? Outdoor reset controls are relatively simple devices that provide ample energy savings and a higher level of indoor comfort during the heating season. Jan 6, 2025 · To change your heating flow temperature safely yourself, you must have a condensing combi boiler. Mar 14, 2025 · Correct Condensing Boiler Temperature Settings Central Heating Boiler Temperature Settings Below we’ll explain how to optimise your boiler’s flow temperature and how changing your units boiler temperature settings can work to potentially save you up to 8% on your energy bills. While these boilers are designed for peak performance at lower temperatures, they are frequently installed with a default flow temperature of 70-75°C. Distribution losses go up at those higher temps for lower as-used system efficiency, and the burn risk of skin in contact with exposed distribution plumbing does too. Is it feasible to have house temperature at 50 degrees in winter and how does that affect the flue gas condensation? If the t stat is set to 50 each time I leave for a week, am I causing damage to the furnace and flue? I assume that the cold water in the system may cause condensation once the circulation starts? I also have I have an older Baxi Solo 18 HE condensing boiler which is working fine. May 30, 2025 · Learn how to adjust water temperature on your boiler. Understanding these settings is key to optimizing the performance of your heating system. We’ll explain what temperature your boiler should be set at for central heating in the UK and what temperature it should be set at for hot water. Need some pic of the boiler, piping and pumps to see how it's piped. 12/21/2022 Boiler What temperature should a condensing boiler be set at? There are so many controls that come with your heating system that it can be difficult to know what each does and what temperature your appliance should be set to. Learn the recommended settings for comfort and efficiency, plus expert tips from iHeat professionals. Understanding your boiler type and familiarizing yourself with standard boiler temperature settings is key to optimizing your system. 68), but that sets the max difference in temperature higher than the reset curve temp and control (whether under return temp or supply temp control). After that, it goes to the set temperature. The temperature is set to 160F on the boiler. Feb 24, 2025 · See more information on how the engineer & contractor can make a decision about what to use in condensing boiler venting materials. I have read that around 180 degrees may be a typical setting for the boiler control, but during my investigations into this system, I noticed that they had it set at 200 degrees. Sep 10, 2025 · Discover the ideal boiler temperature settings for winter to maximise comfort and efficiency. Feb 7, 2022 · Finding the best temperature to set your central heating oil boiler can be quite the challenge. Cranking the temperature too high can waste energy without significantly improving how warm your home feels. Temperature Feb 13, 2024 · Optimal Boiler Temperature Settings For combi boilers, the ideal temperature for radiator output is 75°C, and for hot water, it should be between 50°C and 60°C. It’s very basic with a boiler temperature control. Setting it lower than 60°C increases the risk of legionella disease. Feb 24, 2020 · While a condensing boiler may have an AFUE rating of 95%, this rating was established in a test lab with a constant 140F supply temperature. The hydronic system uses PEX tubes under a concrete floor. If you’re lucky enough to have one of our boilers, here’s where we let you know what temperature a condensing boiler should be set at, or any other of our boilers. Go ahead and play around with it- change the Space Heating supply temperature (should be displayed as parameter A on the information display I have another question about the correct temperature setting for boiler itself. Oct 18, 2021 · A recent report found that turning down the flow temperature on your gas boiler can save 9% on your gas bills. Our guide explores the different boiler settings, including temperature, pressure, and timing, and provides practical advice on how to adjust them to optimise your boiler's performance and save money on your energy bills. This guide will explain what boiler temperature means, how to set it, and provide tips for getting the most out of your boiler. If you’re unsure about the best settings for your boiler type, it’s always a good idea to consult a technician for professional advice and maintenance. ) That generally takes an output temp under 140F or lower. oxscm uiezh qxjk xth qsgd vpwy zdnt cvryr mwgrwnxg luzkf vvld lae kkn ivv npga