Combi cutting out when running shower

[joe brown]

My friend has a combi boiler and is running a shower with a pump, Recently the water has going cold and the boiler has been shutting off, Has anybody any idea. The boiler is ok once you start it again

 

[oldplumber]

I would think that combi and shower pump are not a set up I'd try, pump sucks out to much water hence cant keep up with demand for hot water and runs cold, then your friends combi does the sensible thing and gives up via its pcb closing it down. Out pump and things ok, after all do any of the other draw offs (taps) cause the combi to shuut down?

I may be wrong but it sounds like a good answer. where's Jambo when you need him?. Alternatively get your friend to shower at yours!

 

[payney1974]

pumped shower run off a combi?? Must be a good combi!!

 

[dontknowitall]

I heard today of two boilers cutting out with intermittent faults. One was a result of the incoming mains arcing (speling?) with a metal roof or something similar and only the boiler was affected. The other was the boiler was wired to the same circuit as the shower and had reverse polarity so everytime the shower was used the boiler turned off.

Not saying it's either of these, but could it be some form of electrical fault?

 

[joe brown]

I would think that combi and shower pump are not a set up I'd try, pump sucks out to much water hence cant keep up with demand for hot water and runs cold, then your friends combi does the sensible thing and gives up via its pcb closing it down. Out pump and things ok, after all do any of the other draw offs (taps) cause the combi to shuut down?

I may be wrong but it sounds like a good answer. where's Jambo when you need him?. Alternatively get your friend to shower at yours!

Oldplumber thats the exact advice i gave him, He said it only started very recently though and wondered why it hadnt happened sooner, They have lived there 10 years? I was puzzled too

 

[Kip]

Get rid of the extra pump on the shower, the combi has a pump in the boiler.

As for it only just happening now is that it could be the water pressure in the area has dropped, works going on or whatever it is...

anyhow a power shower shouldn't be used with a combi.

 

[moony]

Get rid of the extra pump on the shower, the combi has a pump in the boiler.

As for it only just happening now is that it could be the water pressure in the area has dropped, works going on or whatever it is...

anyhow a power shower shouldn't be used with a combi.

regardless of pump being in boiler its not for the hot water its for the heating circuit. the hot water is main pressure.

like others have said you dont have a pump running a shower on a combi system, so its worked for a while ? so what - its just not done for the very reason that it doesnt work as is being found out who fitted the pump for them ? shocking to be honest.

 

[Plumbstar Tom]

its against regs to fit a pump on mains whcich a combi is so v bad practice

 

[quality]

its against regs to fit a pump on mains whcich a combi is so v bad practice

No offence here but what about a remote location with low water pressure (mains) surley its allowable to install a pressurisation unit - ( but obviously not to feed a shower 🙄)

 

[charlie frederi]

Hi
Dont think v good idea running a shower pump off a combi as they are mains fed
unless the water pressure is realy low you can fit cold water booster pump on incoming main try removing shower pump and you should solve the problem

Or even a coldwater booster pump to the incoming main before the combi boiler if mains pressure low i am sure pressure unit are for filling systems automatically