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The Daily Insight

What is the best temperature for a condensing boiler

Author

John Thompson

Updated on May 09, 2026

In summary, for optimal operation, condensing boiler systems need the return water temperatures well below the dew point of the boiler exhaust (for natural gas, this is around 140°F in the Bay Area and 125°F in Denver), ideally around 80°F or lower.

What temperature should a condensing boiler be?

You should set the temperature between 60 and 65 °C but for maximum efficiency, it should be set to around 60 °C. Do not set it lower than this as you could increase the risk of contracting Legionnaires’ disease. Legionnaires’ is a form of pneumonia that’s caused by bacteria in water.

What temperature should my condensing boiler be set at in winter?

So, what is the best temperature to set a condensing boiler? The answer is to set your central heating temperature to around 70C, and your hot water to 60C.

What temperature should a condensing boiler be set at for central heating?

An ideal design temperature for a new condensing boiler commercial heating system would be 65°C supply, 45°C return.

What temperature should I set my boiler for heating?

Your boiler controls explained To maximise efficiency, we recommend setting your radiator dial to 75 degrees and your hot water to 60 degrees. Once you’ve got your boiler running at the optimal temperature, you’ll want to set the timer for when you need heating the most. With a combi boiler, hot water is on demand.

How much water should come out of a condensing boiler?

An efficient condensing boiler will generate around 2 litres of condensate water an hour at a temperature of around 30-40°c. This needs to be safely disposed of, within the buildings waste water system.

What temperature should your hot water be?

Professionals recommend keeping your water heater set at a temperature between 130 and 140 degrees Fahrenheit. Any higher, or lower, could actually be dangerous for you and your family. While turning the temperature up higher can result in burns, turning it lower than the recommended setting can also be dangerous.

What temperature should hot water be set at combi boiler UK?

The best setting for combi boilers is often recommended as 75°C for central heating and 60°C for domestic hot water. Turning down the temperature of the domestic hot water is particularly helpful as it can greatly reduce any risk of scalding.

What temperature should my hot water tank be set at UK?

A domestic hot water cylinder thermostat should be set at 60-65ºC. This is high enough to kill off harmful bacteria such as Legionella. If you set the thermostat much higher than this the water that comes out of the taps will be too hot and there’ll be a risk of scalding.

What temperature should a Worcester boiler be set at?

During the winter, the ideal temperature setting should be 18-21 degrees. In areas that get extremely cold, then 21-23 degrees would be sufficient. If you have taken additional measures to retain heat such as wall insulation or draught-proofed windows and doors, then you could set your thermostat to 17 degrees.

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Can I leave my boiler on continuously?

Can I leave my boiler on continuously? You can, but it will cost you more. Once your water reaches a certain temperature, the water heater will turn off. It will turn back on again when the water cools.

What number should boiler pressure be on?

The ideal pressure for your boiler is usually between 1 and 2 bars, but it’s possible it could go up to 2.5 bars when your heating is on. Check the boiler manual to find out exactly what it should be for your boiler make and model. If the boiler pressure is below 1, that means low pressure.

Is 50 degrees hot enough for hot water?

So, what is the best temperature range for your water heater? The EPA recommends 120 degrees because it’s hot enough to keep diseases at bay, it’s not hot enough to cause scalding, it will supply enough hot water for most small families and is relatively energy-efficient.

How long do condensing boilers last?

Generally speaking, you can expect modern boilers to last for around 15 years, or potentially even longer if you get a good quality model and service it regularly. Pay attention to the warranties offered with boilers, and to benefit from added peace of mind, consider getting an extended warranty if possible.

Do all condensing boilers need a drain?

A condensing boiler will produce about 2 litres of condensate an hour at an average temperature of 30-40℃. This condensate needs to drain into your waste water outlet or to a drain via your condensate pipe.

Can boiler condensate go into rainwater?

It is possible to terminate a condensate pipe into a rain water down pipe that terminates into the foul waste system. As with all externally-run condensate pipes, it is recommended to keep the external run to minimum and the pipe diameter to 32mm when exiting the property.

What is the best temperature for radiators?

As a rule of thumb most guidelines recommend heating your home to 70F (21C) and bedroom temperatures should be kept a little cooler to around 64F (18C). For most people this temperature will be comfortable, but if it feels a little hot (or alternatively cold) then the temperature can be adjusted from this baseline.

Is it OK to turn off boiler in summer?

If you have an old boiler — especially one with a continuously burning pilot light — it may well be worth turning off the boiler in the months when it’s not used for heating the home. … However, it’s always best to run your central heating and hot water occasionally during the summer.

Is it cheaper to have heating on low all day?

According to experts at the Energy Saving Trust, the idea it’s cheaper to leave the heating on low all day is a myth. … The Energy Saving Trust says if you’re keeping the heating on all day you’re losing energy all day, so it’s better to heat your home only when you need it.

What is the least expensive way to heat a home?

  • Buy an energy-efficient space heater.
  • Buy a smart thermostat.
  • Use credit cards to pay your utility bills.
  • Sign up for budget billing.
  • Insulate your attic.
  • Invest in warm clothing.
  • Consider installing solar panels.
  • Summary.

Is 2.5 bar too high for a boiler?

In this instance, a reading between 1.5 – 2.5 bar can be considered normal. A consistent 3 – 4 bar, however, is something to raise with a local heating engineer.

What should combi boiler pressure be when heating is on?

The ideal boiler pressure should be between 1 to 1.5 bars on your pressure gauge when your heating is switched off. Around 2 bars is a normal pressure level when your boiler is active/heating up. Anything below 0.5 is too low and must be replaced.

Can a boiler lose pressure without a leak?

If your boiler maintains pressure after this, then it is likely that the problem has been solved. If your boiler continues losing pressure and there is no leak, then there may be a fault with the boiler.

Is 60 degrees too hot for water?

In general, hot water is 130 F (54.4 C) or above. Warm water is between 110 and 90 F (43.3 to 32.2 C). Cold water is generally between 80 and 60 F (26.7 to 15 C).

Would 150 degree water burn you?

Most adults will suffer third-degree burns if exposed to 150 degree water for two seconds. Burns will also occur with a six-second exposure to 140 degree water or with a thirty second exposure to 130 degree water. Even if the temperature is 120 degrees, a five minute exposure could result in third-degree burns.

How often should a condensing boiler be serviced?

How often should you service your boiler? You should always check with your manufacturer, but usually your first boiler service must be conducted 12 months after installation in order to meet the terms of your warranty. It should then be serviced every 12 months on an ongoing basis after this.

How much does it cost to replace a boiler in a house?

Residential boilers can keep your home warm at a relatively low price, but homeowners are responsible for an upfront cost. The average cost to replace a residential boiler is $3,624 to $8,061, which includes installation.

Can a boiler last 20 years?

The life expectancy of a boiler depends on the type of boiler you have. On average, a conventional gas boiler can last for 10 to 15 years given that it is well maintained and serviced annually. If you have a superior quality boiler and it’s well maintained, you can expect it to last for 20 years and more.