Hi, my name is ***** ***** I have been in the plumbing and plumbing repair field for 20 years. I will be glad to help you today. Is the problem isolated to one bathroom?
Hi Mike. No, it's not. We have three bathrooms, plus kitchen taps plus downstairs toilet.
The layout is as follows:
Downstairs toilet and kitchen. Condensing boiler in utility room. Middle floor kids bathroom, also housing unvented cylinder. Middle floor adult bathroom, currently being renovated. Top floor bathroom.
We can get hot water as follows: if I just run hot tap on top floor bathroom, it comes out hot (sink and bath). If I just run any other hot tap, it comes out lukewarm. If I run the middle floor bathroom and the ground floor (kitchen and toilet) taps, then the ground floor taps run hot, while the middle floor continue to be lukewarm.
Is there a new shower valve in the renovated bath? If so what model shower valve is installed?
The renovated bath has a complex four valve mixer installed (handheld, normal shower, waterblade, plus thermostatic control). The renovation is ongoing. There's also a bath, which there wasn't previously.
It's a Zucchetti Agua Blu themostatic shower mixer with three outlets.
Have they installed the cartridges in the new valves?
Not sure, I'll have to ask. What's the significance?
Almost certainly the issue is something to do with the renovation. The shower valve body often does not come with the cartridge installed and will have a cap that comes with it instead. This is so that the cartridge does not get damaged during construction. Without the cartridge installed the hot and cold will mix. Water will go to the point of least resistance so some hot taps will draw hot water from the boiler and others will draw water through the shower valve body and cold water will be pulled through the shower valve causing the hot water to be warm instead of hot. If there are stop valves on the inlet ports of the shower valve then turn them off and that will solve the problem.
Sorry for the delay. My computer decided it needed an update and shut off.
No worries re the delay. Just reading your answer now
If there are not stop valves on the shower then install the cartridge and turn the shower off or if you do not have the cartridge yet (some come with the handles and finish plate) then install a shut off valve on at least one of the water lines and turn it off. That will stop the water from mixing.
Thanks for the answer. Makes sense. The plumber here is now saying something similar, that this is just because the renovation isn't complete so some valves are open and others are shut and that once the renovation is finished, all will be well. Do you reckon I can trust him on this?!
There is not any reason at all that you should have to wait until the renovation is over. Either install the cartridge in the shower and turn the shower handle to the off position or install shut off valves on the lines feeding the shower or install shut off valves to isolate the bath from the rest of the house. There are several ways that this problem could be solved today.
Thanks for that! Very helpful.
Let me know if I can help further. I am about to head out to the dentist but I will be back online when I get back.
You can even comment or ask questions even after positively rating my service. I will always respond. Mike
Thanks Mike. I think I've got all the info I need now. Gonna rate you now. Good luck at the dentist!