Boiler Temperature

moredeadthanalive

I just got a Vaillant condensing boiler fitted and looking forward to cheaper bills. My old one was 22 years old!

The plumber set the hot water tank to 55C. My question is what is the optimum temperature to set the boiler to. Does it have a most efficient temperature to heat the water to? It is currently set to 60C.

penrhyn

Sounds about right for the hot tank, I'd experiment with a slightly higher temperature for the boiler if the tank is not getting hot enough.
Depends how long your boiler is on though, I tend to run my hot water for an hour in the morning and an hour at night.

heating-eng

moredeadthanalive wrote: »

I just got a Vaillant condensing boiler fitted and looking forward to cheaper bills. My old one was 22 years old!

The plumber set the hot water tank to 55C. My question is what is the optimum temperature to set the boiler to. Does it have a most efficient temperature to heat the water to? It is currently set to 60C.

I normally set them about 60c

chopps

What about the radiator water temperature ? 70 C sound ok ?

Is it more economical to have a higher water temp circulated to the radiators (say 80C) for a shorter time to cause the trv on each radiator to switch off or a lower temp(60C?) to circulate for longer ?

At a guess the higher temperature is best as the boiler and pump are on for a shorter time ??

heating-eng

chopps wrote: »

What about the radiator water temperature ? 70 C sound ok ?

Is it more economical to have a higher water temp circulated to the radiators (say 80C) for a shorter time to cause the trv on each radiator to switch off or a lower temp(60C?) to circulate for longer ?

At a guess the higher temperature is best as the boiler and pump are on for a shorter time ??

The lower the temp the lower your bills.

energysavingexp

heating-eng wrote: »

The lower the temp the lower your bills.

i totaly agree but you need to think about Legionella as this is only killed off at temps abouve 70 'C

chopps

Is 70 C ok then for the CH ? (and the previously advised 60 C for the hot water on demand setting)

heating-eng

energysavingexp wrote: »

i totaly agree but you need to think about Legionella as this is only killed off at temps abouve 70 'C

This is incorrect

chopps

70 C is not practical due to risk of injury from it being too hot

RuthnJasper

I've got a Vaillant as well. Mine is set to 60, though I occasionally rack it up a bit in Winter. I'm one of those types who prefers to be cold than hot, though!

It's a REALLY good boiler. I can work it and I'm normally useless with things like this (would prefer it to be a man's job, but the only man in my life at the moment is Jasper-dog, and he views such tasks as beneath him... !).

Incidentally, if you ever lose the operator's manual, I was able to easily download an online version. I have a PDF of it, would be happy to send you the link, should you ever need it.

Best wishes. xx

energysavingexp

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