no hot water upstairs, combi.

[diyplumber1980]

Hi, popped round a mates whos having probs with hot water upstairs. Downstairs hot water is fine. But in upstairs bathroom, bath hot tap runs hot for a min, then cold. Basin shower taps do not get hot, neither does thermostatic shower. Boiler is a vaillant turbo max combi. I cannot figure out whats wrong. No error codes. But pressure on CH gauge showing as 2.5 bar, even though its not running.

 

[1983]

Anything changed recently, ie is this a new bathroom? Is the boiler downstairs? What's your flow rate out of taps at upstairs bathroom?

 

[Madrab]

CH pressure is high, should be in the 1>1.5 bar range, DIY fix is open a bleed valve on a radiator and reduce pressure. When the bath hot water upstairs is on, does the boiler cycle on and off? As 1983 mentions, it may be a flow issue

 

[diyplumber1980]

Thanks for replies lads. Whats the best way to measure flow rate. If i remember rightly, the water was flowing ok, although flow didnt seem powerful. However it seemed enough to get the boiler fired up.

 

[Madrab]

time filling a bucket in the bath/fill sink over 60 secs, measure how much water, that = Ltrs/min. If too much water time it for 30secs and multiply by 2.

 

[duffin]

tried running ALL the hot upstairs at the same time? would indicate a flow problem.

 

[gigz]

Turn the upstairs tap on and see what the boiler does, is it going on and off ?