Long time prepper but new to this site-Northumberland

[Frnc]

Thanks.

Yes, that's what I do. Central heating, fires, and cookers not advertising lol. Happy to answer anything if I can.

Hi and welcome to the forum. Nice to have another expert here. We'll shamelessly shake you down for trade secrets.
FRNC, Myself and a few others have been tussling with getting maximum efficiency from our central heating.
Stats down, timers adjusted, flow temp adjusted, Stats moved.

So, I'll throw in a starter question...
Flow temperature on a Vailant Combi system. It was on 70. I dropped it to 60, then lower. Some sites advise even lower. Result seems to be that it takes longer to get rooms warm, but costs less. How low can I go before the condenser thingy stops being able to condense and boiler efficiency drops off the charts?

HIya,

Thanks jennyjj01,
I wouldn't go below 60 myself, there won't be any benefit in terms of heating your house and you will still be using fuel.

For example, the air source heat pumps that are expected to do the heavy lifting of replacing fossil fuels only get to 55 deg C on the flow pipes. And that isn't suitable for the vast majority of homes. To compensate for this the dwelling needs a very high level of insulation and also much bigger radiators than the normal spec for a room. It can be of use to an underfloor heating system however where temps are best served lower.

The best solution in my humble opinion would be to have someone develop an infrared heater. It's much more efficient than radiated heat which heats up the general area. So if you stand outside on a cold day and it's a sunny day with no wind, it may be 4 or 5 C or whatever but when you stand in the sun you can feel the warmth on your skin.

Best to run the boiler at 60 and use different rooms as zones so you can reduce the size of the heating system. Thermostatic radiator valves in spare rooms can be turned down to "1" for example. That will stop heat from being wasted but also stop dampness. Then the boiler will run shorter cycles keeping the rest of the zones warm.

There is lots of conflicting advice and the theory seems to change re leaving the heating on all day or switching it off when at work and going full-on when you get in. It depends on lots of factors. Also for the boiler to condense the system should be balanced so that the radiators are consistent temps across the whole system. And the return used to be optimal for a condensing boiler if it was approx 15/20 deg c lower than the flow temp.

Sorry for late response it's a bit manic this time of year!

How can rads be consistent temps across the system if you have some turned to 1 and others on full blast?

[jennyjj01]

HIya,
I wouldn't go below 60 myself, there won't be any benefit in terms of heating your house and you will still be using fuel.

The best solution in my humble opinion would be to have someone develop an infrared heater. It's much more efficient than radiated heat which heats up the general area.

Thanks for that. Yes opinions vary on whether to run constant and low or cadanced and high. If it is a science, there's lots of opinions without scientific basis, especially from politicians.

There's a member here that swears by electric infra-red wall heaters. Instant heat delivered straight to the body. Though electricity is dearer than gas, that can still cost in by not heating the room.
viewtopic.php?p=210145&hilit=infra#p210145

[FireTube]

Hi and welcome to the forum. Nice to have another expert here. We'll shamelessly shake you down for trade secrets.
FRNC, Myself and a few others have been tussling with getting maximum efficiency from our central heating.
Stats down, timers adjusted, flow temp adjusted, Stats moved.

So, I'll throw in a starter question...
Flow temperature on a Vailant Combi system. It was on 70. I dropped it to 60, then lower. Some sites advise even lower. Result seems to be that it takes longer to get rooms warm, but costs less. How low can I go before the condenser thingy stops being able to condense and boiler efficiency drops off the charts?

HIya,

Thanks jennyjj01,
I wouldn't go below 60 myself, there won't be any benefit in terms of heating your house and you will still be using fuel.

For example, the air source heat pumps that are expected to do the heavy lifting of replacing fossil fuels only get to 55 deg C on the flow pipes. And that isn't suitable for the vast majority of homes. To compensate for this the dwelling needs a very high level of insulation and also much bigger radiators than the normal spec for a room. It can be of use to an underfloor heating system however where temps are best served lower.

The best solution in my humble opinion would be to have someone develop an infrared heater. It's much more efficient than radiated heat which heats up the general area. So if you stand outside on a cold day and it's a sunny day with no wind, it may be 4 or 5 C or whatever but when you stand in the sun you can feel the warmth on your skin.

Best to run the boiler at 60 and use different rooms as zones so you can reduce the size of the heating system. Thermostatic radiator valves in spare rooms can be turned down to "1" for example. That will stop heat from being wasted but also stop dampness. Then the boiler will run shorter cycles keeping the rest of the zones warm.

There is lots of conflicting advice and the theory seems to change re leaving the heating on all day or switching it off when at work and going full-on when you get in. It depends on lots of factors. Also for the boiler to condense the system should be balanced so that the radiators are consistent temps across the whole system. And the return used to be optimal for a condensing boiler if it was approx 15/20 deg c lower than the flow temp.

Sorry for late response it's a bit manic this time of year!

How can rads be consistent temps across the system if you have some turned to 1 and others on full blast?

[Because as I already mentioned in the same post you have reduced the size of the "system". The ones turned down are just ticking over.]

[Frnc]

Because as I already mentioned in the same post you have reduced the size of the "system". The ones turned down are just ticking over.

Oh of course. The rads at 1 just run for less time.