new shower installed, hot water cuts out

[cherpel]

Vaillant combi boiler, 15 years old, works well and is serviced regularly (kept insurance going). New shower on top floor (boiler 3 floors down) has hot water for only 5 mins or so before boiler cuts out. Why? What do to? Flow in house has always been low, but at least once it gets hot, it stays hot - but not in new shower.

 

[manutd4life]

before the shower was installed, were there anything else on the same floor/room that had hot water? Is your pressure from the boiler dropping?

 

[Andy™]

maybe too little flow so boiler is overheating and cutting out?

maybe try a tap on a low floor slightly open at the same time to get a little more flowing and see if it lasts any longer?

 

[manutd4life]

[quote name='Andy

 

[Andy™]

I imagine you would lose even pressure in the new room if you open another tap elsewhere. Might need to get yourself a circulation pump

probably, although you may then get enough flow to keep the boiler on to find out if it is the lack of flow thats the problem

 

[SLIPSHOD & SLAPDASH]

A 15 year old combi still working, thats amazing anyhow. If the water goes cold but then will warm up again later without having to reset anything its more than likely the Hot water heat exchanger. They are only about the size of a sardine can and do get blocked with silt, limescale etc.

 

[manutd4life]

A 15 year old combi still working, thats amazing anyhow. If the water goes cold but then will warm up again later without having to reset anything its more than likely the Hot water heat exchanger. They are only about the size of a sardine can and do get blocked with silt, limescale etc.

I dont think he is saying it goes cold but will then warm up. If it gets warm then goes cold i imagine the boiler isnt able to apply enough pressure to reach your new shower room, the cold will get there as that is fed from the mains direct from outside and that will be more presurised. I imagine a new boiler would manage it but that can be expensive. I would have a look at getting a circulation pump.

 

[SLIPSHOD & SLAPDASH]

You cant pump a combi boiler, it doesnt matter as the OP will probably never return here,