I have a back boiler with a thermostat on the top of it, scaled from 1-6. I
also have a room thermostat which just controls when the heating works as
far as I can see.

My question is what should I have the boiler thermostat set on? It is now on
'4' but is it more efficient to have it set on 5 or 6?

The hot water temperature seems ok, slightly too hot to hold your hand under
for long but I assume thats ok.

I am new to all this, as this is my first house so go slowly

Thanks,

Phil

My question is what should I have the boiler thermostat set on? It is now
on
'4' but is it more efficient to have it set on 5 or 6?

The boiler thermostat controls the water temperature within the central
heating pipework. It basically determines how hot the radiators get.

The room thermostat turns the entire system on or off depending on how hot
the rooms are (not the radiators).

In terms of thermodynamic efficiency, any boiler (not just condennsing
types) will be more efficient at lower temperatures, so low is best.
However, there are two caveats:

1. This will promote condensing. Whilst modern condensing boilers have down
firing burners and drainage systems to take the acidic condensate away, and
ancient back boiler will have no such features. If water starts coming down
the flue, or forming on the heat exchanger, it will corrode. You'll probably
have to turn it well low to cause this, however.

2. You can't turn it so low that the radiators can't heat the room, or the
hot water cylinder never gets to temperature. The hot water cylinder stat
must be set at least five degrees below the water flow temperature, or it
may never turn off.

'4' sounds fine, provided the house gets hot enough and your hot water stat
is set reasonably low (i.e. 55C or thereabouts).

Christian.

cheers christian, the house is heating up just fine so it seems ok to leave
it set as it is.

now i am gonna sound dense... but where might the hot water stat be?



"Christian McArdle" wrote in message
t...
My question is what should I have the boiler thermostat set on? It is now
on
'4' but is it more efficient to have it set on 5 or 6?

The boiler thermostat controls the water temperature within the central
heating pipework. It basically determines how hot the radiators get.

The room thermostat turns the entire system on or off depending on how hot
the rooms are (not the radiators).

In terms of thermodynamic efficiency, any boiler (not just condennsing
types) will be more efficient at lower temperatures, so low is best.
However, there are two caveats:

1. This will promote condensing. Whilst modern condensing boilers have
down
firing burners and drainage systems to take the acidic condensate away,
and
ancient back boiler will have no such features. If water starts coming
down
the flue, or forming on the heat exchanger, it will corrode. You'll
probably
have to turn it well low to cause this, however.

2. You can't turn it so low that the radiators can't heat the room, or the
hot water cylinder never gets to temperature. The hot water cylinder stat
must be set at least five degrees below the water flow temperature, or it
may never turn off.

'4' sounds fine, provided the house gets hot enough and your hot water
stat
is set reasonably low (i.e. 55C or thereabouts).

Christian.

now i am gonna sound dense... but where might the hot water stat be?

It should be a little box near the bottom of the hot water cylinder. It may
have a knob on it, calibrated in celcius. It will have a flex coming out
wired into a nearby junction box. It may be held on with a plastic strap
that goes all round the cylinder. You may confuse it with an immersion
heater, if you don't know what you are looking for.

You may not have one, in which cause, you should fit one and use it to
control the zoning arrangements. Otherwise, you are throwing money away.

Christian.

hmm... no little box at the bottom...

shall i just chuck a wad of cash in the middle of my room and burn that
instead?

so how easy are these things to fit then? grin

just one more thing... 'aren't newsgroups brilliant!'




"Christian McArdle" wrote in message
t...
now i am gonna sound dense... but where might the hot water stat be?

It should be a little box near the bottom of the hot water cylinder. It
may
have a knob on it, calibrated in celcius. It will have a flex coming out
wired into a nearby junction box. It may be held on with a plastic strap
that goes all round the cylinder. You may confuse it with an immersion
heater, if you don't know what you are looking for.

You may not have one, in which cause, you should fit one and use it to
control the zoning arrangements. Otherwise, you are throwing money away.

Christian.

so how easy are these things to fit then? grin

It could be anything from extremely simple to very complicated, depending on
what you have installed.

The following information should help in determining what your current
system is. We already know it is a back boiler.

1. How many pipes come out of the boiler? How large are they?

2. Does your programmer allow you select the heating, but have the water
turned off, or are you forced to have the water on? (Or you can turn the hot
water off, but it has no effect, the hot water cylinder is heated anyway).

3. Can you hear/feel the pump operating when the heating is off, but the hot
water is turned on?

4. Are there any zone valves? These are large valve, that look like a
stopcock, except the handle has been replaced by a plastic box about 8cm x
8cm x 6cm which a flex trailing out. We need to know how many such valves
you can find, where they are installed, and how much pipes come out of them.

Christian.

manoman wrote:

cheers christian, the house is heating up just fine so it seems ok to leave
it set as it is.

now i am gonna sound dense... but where might the hot water stat be?


Strapped to or inserted in teh HW tank.