Turn your boilers down to 60C to cut energy bills, households to be told

brewerdave

@[Deleted User] - are you getting enuf energy from the solar panels currently to achieve 65 deg C or are you heating with imported energy from the grid ?

[Deleted User]

are you getting enuf energy from the solar panels currently to achieve 65 deg C or are you heating with imported energy from the grid ?

It depends. Yesterday it was 100% from my roof. The day before, it came mainly from the Grid (off-peak). Re-heating via gas uses somewhere between 6 and 8kWh (depending on the number of baths/showers) whereas re-heating via electricity uses somewhere between 2 and 4kWh.

Astria

Deleted_User said:

Legionella is just not really a thing to worry about in a domestic environment, unless you're doing something extreme or unusual.

and don't forget that it's typically only stagnant water that it applies to, so even if you only heat your hot water to 50c in your hot water tank, if you use it every day there's next to zero chance of catching legionella. If your tank does spend a lot of time in the "danger zone", you could, once a month, bring the tank temperature upto 60c to kill any possible trace in the system.

Showers are typically far worse for legionella growth than your hot water tank however, as they typically always run in the 37c or thereabouts, but even then, there isn't typically enough of it to cause problems and I expect most people clean there shower heads at least once every few weeks as a minimum.

Chrysalis

My boiler just has 1-4 no temp markings.

tux900

Auti said:

I have an Ideal Icos installed April 2006 with separate water tank (no immersion) in airing cupboard. Because of legionella I have turned up tank heating up to 60 degrees but am at a loss to understand what the markings on the dials mean on the boiler -photo below.

The Icos has a flow temperature range of 30 - 82°C so with five gradation steps each step would be roughly 10°C, thus 30°C, 40°C, 50°C, 60°C, 70°C and 80°C. So you're are likely around 65°C at the moment. The absence of numbered markings suggest it is likely only approximate but it ought to be a reasonable starting point.

rrl28

I turned mine down from 70 to 60 and it took an hour longer in the morning for the house to get up to temperature and it did not seem to reduce my gas consumption by any visible amount because the boiler was on for longer.

Also my boiler reduces the temperature of the water after the house heats up anyway to maintain the set temperature.

[Deleted User]

I turned mine down from 70 to 60

A lower boiler flow temperature results in a lower flow return temperature, and increased boiler efficiency. It’s basic physics. My boiler has been cutting in and out all day on what has been a very cold; foggy and miserable day: usage so far today is 25kWh on a 24kW boiler.

I have a week to go until my smart gas meter reaches its 2nd birthday. To date, we have used 1127 M3s or an average of 6400kWh a year. 

Yes, the boiler is on longer but running the boiler at a lower flow temperature does cut down on usage. It is also a useful test of whether your radiators are big enough for a heat pump.

tux900

Dolor said:

It is also a useful test of whether your radiators are big enough for a heat pump.

Yes, that's something I intend to test this coming winter - turning the flow temperature down to 40°C or so and seeing if / how well we manage to keep the house warm.

facade

Astria said:

Showers are typically far worse for legionella growth than your hot water tank however, as they typically always run in the 37c or thereabouts, but even then, there isn't typically enough of it to cause problems and I expect most people clean there shower heads at least once every few weeks as a minimum.

Crikey! that often?!

I only clean mine when the water stops coming out, looks like I'll have to start....