Ideal Combi hot water but noi heating

[fiddler3]

Hi all. Daughter's boiler again thanks for help last year.
New problem - hot water works fine, but when calls for heat boiler starts and runs for a few seconds then stops. No error messages.

My thought is that pump is inop, so boiler starts up but then switches off when the small amount of water in the heat exchanger reaches temperature but doesn't circulate.

Would be grateful for any other ideas before I plan who to get to fix it (expensive with D&G if it is just a new pump).

 

[Scott_D]

Are there zone valves? (New build)
Have you shut any thing off under the boiler

 

[fiddler3]

Are there zone valves? (New build)
Have you shut any thing off under the boiler

Thank you, no to both - old build and daughter doesn't fiddle with boiler and I cant investigate/ fiddle as am acting remote due to current situation and distancing.

 

[garygvl]

If you’ve got a combi and hot water is working fine but you have no heating it ain’t a pump problem

 

[moonlight]

Has it been serviced recently? I went to one the other day. Some had the the valves closed on the filter.

 

[Scott_D]

Can you get some pictures of the valves underneath and the controller/thermostat

 

[Stu-B]

Has she been topping up the pressure and turned off the wrong valve? Common issue on these as the levers are all next to each other and difficult to see if the boiler is low down.

 

[fiddler3]

Thanks to you all - unfortunately I can't get to look at the boiler or photograph (geriatric distancing) but my daughter is well versed in top up and valve manipulation (prior to heat exchanger replacement last year - thanks for advice on this forum) and hasn't had to top up since then so hasn't touched boiler since. Both CH and hot water were fine until sudden loss of CH a week ago.
Would be interested to hear tech basis for Garygvl saying that it can't be a pump problem.

 

[Gasmk1]

Thanks to you all - unfortunately I can't get to look at the boiler or photograph (geriatric distancing) but my daughter is well versed in top up and valve manipulation (prior to heat exchanger replacement last year - thanks for advice on this forum) and hasn't had to top up since then so hasn't touched boiler since. Both CH and hot water were fine until sudden loss of CH a week ago.
Would be interested to hear tech basis for Garygvl saying that it can't be a pump problem.

because if its a Combi the pump also works for hot water it pushes the water around the heat exchangers