Gas used running a boiler at different temperatures?

Zither

Here is a related question too - my boiler is warm to the touch on the outside (like any boiler is). Unfortunately it’s in the utility room so the heat doesn’t get dispersed back into the house - should I put some insulation around the boiler? Would this mean less heat is lost from the boiler?

thorganby

Norman_Castle wrote: »

Ideally the boiler would measure the return temperature and adjust accordingly or display the return temperature. Why don't they do this?

Many boilers do this and modulate the heat output to match the requirement, some will display the return temp as well as the set flow temp.

Zither wrote: »

Yeah I agree - in a perfect system it would use the same amount of gas. I just didn’t know if there were other things that meant, for example, that a boiler might waste more gas the higher the boiler output temp is set at. After getting new boiler I’m on a bit of a budget so keen to save as many pennies (whilst staying as warm) as possible!

If the boiler flow temp is set too low then the desired room temp may never be achieved and this will definitely waste gas, as the room stat will constantly be calling for heat.

You seem obsessed with how much it costs to use your boiler, most people want to heat their property quickly rather than achieve maximum efficiently and have to wait much longer.

Only a fool would set the boiler flow temp to 50 degrees for a radiator system to try to save a few pence. This setting would only be used for a wet underfloor system.

northernsoul

This morning
Start 07:30. Stat Temp start 14C. Target 18C. Outside 4.5C. Boiler 55C. Gas reading 7349.08.
09:30 Stat temp (not noted but guess around 16), gas reading 7350.53 (used 1.45m3, £0.43 at my tarrif)
10:30. Stat temp 17C, gas 7350.99 (used 0.46m3, and £0.13)
11:30. Stat temp 17.5C, gas 7351.3 (used 0.31m3 and £0.09)

bris

Norman_Castle wrote: »

Ideally the boiler would measure the return temperature and adjust accordingly or display the return temperature. Why don't they do this?

I recently adjusted mine to 65 degrees to get a lower return temperature. This gives a more constant room temperature than the previous overheating then switching off for long periods while cooling.

You're confused about how the return temperature works.


The return temp is all about balancing your radiators. Dropping the flow temp will obviously drop the return temp. A properly balanced heating system is done with the lockshields on the radiators.

northernsoul

"If the boiler flow temp is set too low then the desired room temp may never be achieved and this will definitely waste gas, as the room stat will constantly be calling for heat."
With the actual real world tests I did this was not the case. Even though the boiler at 55C never reached the target temp it still used (much) less than boiler set at 65C which did reach target temp and maintained it.

Norman_Castle

bris wrote: »

The return temp is all about balancing your radiators.

Aren't the radiators balanced so they get an equal share of the available heat?

Zither

northernsoul wrote: »

This morning
Start 07:30. Stat Temp start 14C. Target 18C. Outside 4.5C. Boiler 55C. Gas reading 7349.08.
09:30 Stat temp (not noted but guess around 16), gas reading 7350.53 (used 1.45m3, £0.43 at my tarrif)
10:30. Stat temp 17C, gas 7350.99 (used 0.46m3, and £0.13)
11:30. Stat temp 17.5C, gas 7351.3 (used 0.31m3 and £0.09)

You use so much less gas than me. My boiler seems to use roughly 1 unit (eg 1 number on the gas meter) per hour at around 60 degrees on the boiler...

northernsoul

Its only set at 55C (granted not far from your 60c) and stat set at 18C. Got to 18C at 12 , 4.5 hours after starting at 14C (helped by the sun ! ).
Your boiler is set about 60C, what about stat target temperature? Where roughly do you live ( only say roughly just to be safe , ) because if in Scotland that will make a fair difference.
Unfortunately non of the next 5 days are like my test days but may run boiler at 75C on one of the next 5 days. Will still for definate do it when/if the temps are the same.
After all "Thorganbuy" said "Only a fool would set the boiler flow temp to 50 degrees for a radiator system to try to save a few pence. This setting would only be used for a wet underfloor system" , so i must be very nearly a fool ! Haha

shortcrust

Zither wrote: »

Haha yes I’ve also been wondering about how much vapour these condensing boilers are supposed to create. At 80 mine also kicks out a lot more vapour than my old system! Maybe time to turn it down to 60

Would be v interested how you get on with IR temperature gun - was thinking about doing the same... when I buy one (or I could just spend the money it would cost on actual heating haha.

It doesn't work very well unfortunately, I think because the pipes are too reflective. However, the return pipe is way too hot to touch. I'd guess it's much hotter than 55c.

Alex1983

On a correctly balanced radiator you will have a 20c difference across flow and return so the return should be around 20c below the flow temperature which is the temperature most boilers display.