Solved

Combi boiler uses gas when it pumps water around the rads every hour or so - is this normal?

  • 9 September 2022
  • 7 replies
  • 2242 views
B
Rank

Now my smart meter shows gas too, I notice without using any hot water nor central heating, when the boiler pumps water around the rads for around 90 secs (I gather it’s to help stop the rads silting up), it also lights up during that time, though the outflow pipe hardly gets warm. The result is 0.15kwh of gas used, EVERY HOUR or so.

No gas is used when the boiler is switched off.

 

Does burning gas help prevent silting up?

Or are boiler makers just oblivious to waste?

Can I somehow stop the gas usage when it’s just pumping around?

(Even in winter the central heating is off at night, so why use gas then?)

What’s the risk to the silt situation (I have filters) of keeping the boiler switched

off when not in use (like all summer just turning it on for hot water)?
 

thanks Danny

 

 

 

icon

Best answer by bartokg1 9 September 2022, 18:47

View original

7 replies

C
Rank
Userlevel 3
Badge +1

This is most likely a frost protection feature or it could just be a fault but its not all combi boilers that do it & if it is a frost protection you should be able to disable it 

juliamc
Rank
Userlevel 7
Badge +2

I think it might be a fault as I remember I noticed this happening with my parents’ gas boiler a few summers ago, firing up for no reason. Maybe needs checking with your friendly boiler engineer? I think a switch of some sort was replaced??

B
Rank

Hi all - thanks for your ideas.

I phoned Worcester/Bosch, boosted by your suggestions.

He said if you don’t press the eco button after you have switched the boiler back on,

it stays by default in pre-heat mode, and keeps the boiler (heat exchanger?)

at 54C no less, so when you take hot water it arrives at the tap a bit faster.

 

So you’re burning gas 24/7 to avoid those precious painful extra seconds

of waiting for your hot water to arrive!

And that’s not the opt-in setting, it’s the default!

 

I’ll check the eco setting stops this happening, and count those extra seconds

for your informed decision-making.

 

Hoping all boilers that do this can be undone,

and everybody who has one doing it realises it and solves it as easily.

 

As for the regular silt-avoiding pump stints, the man said it’s not good

for them not to take place, but you can’t stop punters switching their boiler off.

Cheers!

 

 

juliamc
Rank
Userlevel 7
Badge +2

Wow, that seems very wasteful ! and yes, a bad idea as a default. I suppose it’s an example of how we got used to cheap gas so burning a bit more just to make life comfortable.

Last summer was the first time I turned off my pilot light when I realised how much it was burning, even though the heating wasn’t on for 3 monthsÂ đŸ˜¶ I’d let it burn every summer for years !!!

B
Rank

Thanks - so how much was your pilot light burning?

 

juliamc
Rank
Userlevel 7
Badge +2

I would say about 4kWh per day.

B
Rank

Wow I would say that sounds too much, but if you’re down to zero

without the pilot that’s it! Again how wasteful manufacturers are

when nobody knows about it.

Reply


Terms & ConditionsCookie settings