Can anyone solve this problem?

[Chrisgy]

We fitted a new boiler in a care home, the taps are all fine apart from one which goes very hot to cold in about 10 seconds.

The system has 2 boilers and 3 cylinders, 1 cylinder downstairs next to the boilers and 2 upstairs linked together. We have replaced one boiler so far.
All the cylinders get up to temp, I waited for both boilers to go off and the cylinders were all hot. Every tap runs fine constant temperature of about 40C on thermostatic mixers.
The problem is with one bath tap which was fine before, runs a lot faster than the others at about 55C for a few seconds then stone cold.
Something even more strange is one of the boilers fires up when this tap is running?

 

[steve sanders]

We have a shower dripping - it is an A & J Gummers 1861 shower ! Does anyone have the same problem ?

Steve Sanders

 

[Chrisgy]

We have a shower dripping - it is an A & J Gummers 1861 shower ! Does anyone have the same problem ?

Steve Sanders

http://www.ukplumbersforums.co.uk/showers-wetrooms/2674-j-gummers-1861-a.html

So any ideas with this hot water anyone? The staff are having to bucket water to the bath so it needs sorting asap

Only things I thought of was a faulty TMV valve but that wouldn't explain the heat only boiler deciding to think it's a combi, or the tap piped to flow/return pipes but it wouldn't of worked before....

 

[Gray0689]

A tap can't make a heat only boiler fire up!!!!!!!
And tap sounds like it is tmv problem

 

[BLOD]

I'd be looking at the tmv first as well
can you isolate the hot coming from the cylinders to the taps, then test them one at a time to see if a particular cylinder is linked to the problem with the bath tap ?

 

[steve sanders]

what is a faulty TMV valve Chrisgy ?

Steve

 

[Chrisgy]

A tap can't make a heat only boiler fire up!!!!!!!
And tap sounds like it is tmv problem

I know that, but honestly everything gets up to temp and as soon as you run that tap and it goes cold the boiler fires up. I'll check the TMV and hope the boiler fired up 5 times whenever the tap was running by coincidence, that's all it can be I think

I'd be looking at the tmv first as well
can you isolate the hot coming from the cylinders to the taps, then test them one at a time to see if a particular cylinder is linked to the problem with the bath tap ?

Nothing from what I could see, but checked all cylinders when the tap ran cold and they were all hot

 

[MarkAqua]

Trace the pipework back from the bath just to make sure everything is running to the right places first.
Does the bath have a TMV? Is it integral to the tap or seperate? like a Hornes or similar.

 

[BLOD]

if the system's got a secondary return on the hot water check any other tmv's & mixer taps in the bldg as well.

 

[GQuigley67]

have you tried adjusting the temperature on the TRV ??? sounds like its cutting to cold when the hot gets too hot to prevent scalding.

 

[stevetheplumber]

tmv pipework reversed sounds a possibility i realy cant see any link to the boiler

 

[steve sanders]

what is tmv pipework Steve ?

 

[GQuigley67]

Thermostatic Mixer Valve - TMV

 

[MarkAqua]

I doubt pipework is reversed if it was running fine before hand. What make of TMV is it?

 

[steve sanders]

I do not know what make the TMV is ? How would I ?