Boiler firing up but no ch

[Nicola84]

I've noticed my boiler keeps firing up but the central heating not coming on, the thermostat is set to 16 so not expecting the heating to come on as its quite mild , the boiler fires up and heats to 70 then turns off but no one was using the hot water?. Am I going crazy or should I call someone out?

 

[Aire]

If your on a combi it's probably the hot water pre heat

 

[townfanjon]

As above from Craig

Have you got a combi or a boiler and a cylinder

 

[rpm]

Storage combi

 

[Nicola84]

It is a combi

 

[rpm]

Storage combi

It is a combi

Found that in a previous post, guess it must a quiet night because you`re not getting much help here tonight.

 

[Aire]

Found that in a previous post, guess it must a quiet night because you`re not getting much help here tonight.

How much help does she need Her question was answered in the first post an hour after she asked the question

 

[rpm]

If your on a combi it's probably the hot water pre heat

REALLY, is that all you are prepared to say, probably!

How much help does she need Her question was answered in the first post an hour after she asked the question

A little more would help the lady Craig, maybe an explanation of why and what to help her understand would of been nice.

 

[AMGasServices]

Please check if you’ve got any dripping taps in the house as this may cause the boiler to stay in hot water mode.

If that’s all fine I’d advise you to call a gas engineer out.

 

[Aire]

Ok, to please @rpm as he's clearly on his monthly.

The pre heat feature of a combi is there to keep your hot water heat exchanger hot. The reason is so you save water as you don't have to draw off as much water before hot water is delivered to the tap.
So a couple times a day you may notice your boiler fires up for apparently no reason. All it's doing is heating up your central heating water within the boiler and passing it through the hot water heat exchanger to keep it hot so it's ready for when you require hot water.

I don't fully agree with amgasservices idea of a dripping tap keeping the boiler in hot water mode as more than a drip would be required for that. However if you do have 1 or 2 dripping taps, this will cool the hot water heat exchanger quicker when not been used so you may find your boiler firing up more frequently to keep it hot.

Hope this helps and satisfies @rpm

 

[rpm]

Ok, to please @rpm as he's clearly on his monthly.

Hope this helps and satisfies @rpm

****!

 

[Harvest Fields]

Where is the boiler located? Is there an external frost stat?

 

[Harvest Fields]

Ok, to please @rpm as he's clearly on his monthly.

The pre heat feature of a combi is there to keep your hot water heat exchanger hot. The reason is so you save water as you don't have to draw off as much water before hot water is delivered to the tap.
So a couple times a day you may notice your boiler fires up for apparently no reason. All it's doing is heating up your central heating water within the boiler and passing it through the hot water heat exchanger to keep it hot so it's ready for when you require hot water.

I don't fully agree with amgasservices idea of a dripping tap keeping the boiler in hot water mode as more than a drip would be required for that. However if you do have 1 or 2 dripping taps, this will cool the hot water heat exchanger quicker when not been used so you may find your boiler firing up more frequently to keep it hot.

Hope this helps and satisfies @rpm

I have seen the heating on a Baxi combi 80 not come on because a bathroom tap had a drip. So yes in my opinion this can actually happen mate.

 

[Aire]

I have seen the heating on a Baxi combi 80 not come on because a bathroom tap had a drip. So yes in my opinion this can actually happen mate.

Really? Wouldn't think they'd be that sensitive but I'll take your word for it. However, op isn't saying her heating isn't coming on. She's saying it fires up, goes to 70 then shuts off which would most likely point to a pre heat.