Heating vs hot water...can this happen?!

LuciaM · Feb 11, 2020

Hi there, we have bought a new house and been in for 8 months. We have a Hollywell heating system with 2 thermostats, one for the downstairs and one for the upstairs, in the master bedroom. The back of the house was connected up wrongly, so the back house downstairs came on with the upstairs thermostat and the master bedroom and back of the house upstairs with the downstairs thermostat. After 5 plumbers visits, they finally accepted it was the way the rads had been plumbed in and switched the pipe work around (7 holes in the ceiling so far....). He thought he had cracked it until he found the lounge one still was running off the upstairs thermo and had the return going back into the system incorrectly, so he fixed that too, so it now works on the downstairs again.

Now, the other problem we have had since moving in is when you turn the hot water on, you get a loud bang and then the thermostat on the hot tank resets, so the water never really gets hot. The plumber says it is nothing to do with the heating problem and thinks it’s thermal shock where the hot meets the cold and as the valves are all plumbed in right, he has said that the hot tank pipes need to be elongated to increase the surface area that the water mixes over......but, since he has fixed the downstairs rad return going back into the right place, we haven’t had the bang....... is it possible that the two could have been related? He says no chance they are related, but......I honestly can’t face them coming to do more work if it doesn’t actually need doing now. Equally, if it is thermal shock, I am worried there may have been damage to our boiler?

all help gratefully received.....

moonlight · Feb 11, 2020

You need to get all this sorted out before the warranty expires. Put things in writing, if necessary get an independent company in to do a report. I have completed one for someone who had bought a new property with a leak in the wall on their heating system. Long term it may be worth the expense.

LuciaM · Feb 11, 2020

moonlight said:
You need to get all this sorted out before the warranty expires. Put things in writing, if necessary get an independent company in to do a report. I have completed one for someone who had bought a new property with a leak in the wall on their heating system. Long term it may be worth the expense.

Thank you moonlight- turns out the bang hasn’t gone either and is back with a vengeance when you turn the hot water off.
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LuciaM said:
Thank you moonlight- turns out the bang hasn’t gone either and is back with a vengeance when you turn the hot water off.

Do I just need a normal plumber to do a report? Sorry for asking!

moonlight · Feb 11, 2020

Look for a plumber, probably one who comes highly recommended. If you don't know anyone in your area. Look on the Charted Institute of Plumbing and Heating Engineers website for someone in your area that is an approved engineer. Explain what you need. I am sure there will be someone who can help.