No hot water by using gas boiler but radiators are working fine.

chamomile

5 days ago, we got the old taps replaced by a stange plumber. At first he tried to turn all the valves closed in the cylinder tank room to stop water running before starting his job.

Struggling for quite some time to find the right valve to stop hot water running(he went up to the attic as well), finally, he realised that he didn't turned the valve fully to the right to close it.

After he left, one of the taps are shakey, very loosened, the H/C top signs were wrongly positioned and the black rubber rings sticking out.

I told him about those issues before he left, he just said they are ok like that. Being very disappointed and starting to doubt his professionalism, I just let him go because I knew I could fix those small issues myself.

The problem is that we couldn't get hot water in ths house using the gas boiler since that night. The radiators are working fine I checked. And we got the boiler serviced 3 months ago.

I texted him about that he said he would come by the next day but he didn't show up and he is now out of contact.

I still think that the boiler itself seems ok. Possibly it has something to do with one of the valves he touched. Maybe he forgot to turn some of the valves back to where they were.

Luckily 2 days ago, we found out that we can use electric immersion to get hot water which we had never used before.

Greatly appreciate it if anyone could give some tips/info of what I could do to check what could cause this issue.

And also, should the red valve on the bottom of the cylinder tank be turned open or closed?

Wearb

See if the valve on your cylinder coil is turned partially on, maybe fully on this time of year.

Count the turns, so that you can put it back to where it was, in case that doesn't turn out to be the problem.

chamomile

Thank you very much for your comment! I will try that way.