Why is the water pressure non existence for hot water supply to shower?

[Hannah]

We bought an Edwardian semi detached house just over a year ago (previously a hotel, converted in the mid 90s).

The shower (not power or pumped) had low pressure for hot water which got worse over time, then out of nowhere (hadn’t got round to getting anyone to look at it) it was great, better than it had been when we moved in, but unfortunately over time it has got worse again.

I called out a plumber this week who said it might be the cartridges/heat exchanger, but when he took it apart said it was an issue with the hot water supply to the shower, there’s only a dribble coming through now. He then hoovered the supply pipe from the shower (I believe to see if it would dislodge a lime scale blockage or air lock) which made no difference, at that point he put it back together and said he would do some research and come back to me. We’ve called a few times and the say they’ll come back to us but I get the impression it requires a bit of investigation and they’re not particularly interested. Does anyone have any thoughts? Is there anything we can try? We only have one shower and it is cold only at the moment!

I’ve attached some photos of the hot water tank in the airing cupboard in case this provides extra information to those who know what they are looking at!

 

[Aquarius]

Hi Hannah, good idea with the photos, are you able to show the pipe coming out of the cylinder?
Check the head and hose, simple idea of remove the hose from the shower outlet and operate the shower for hot, if this is ok, points to a head/hose blockage/kink in hose.
Also I'd be checking the cold water storage cistern in the loft, make sure it has water and is refilling ok. This works on gravity, so the distance from the shower head to the base of the cistern is relevant.

 

[Ric2013]

What state of cleanliness is your cylinder feed cistern in, and is it running empty and letting air into the pipework? Two questions I'd be asking myself. Has your plumber tried backflushing the pipework in the opposite direct to normal flow?

By the way, that cylinder installation is shoddy and you'll lose a lot of heat from the cylinder into the pipework due to the way the pipe runs have been installed. To see that kind of work suggests an unqualified (or slapdash) plumber has been in there. If the same person has done a lot in that building, I can understand why some plumbers would rather rip out and start again, as faultfinding could be a pain in the neck! Sorry - probably not what you wanted to hear, and I hope I'm wrong!

 

[moonlight]

Gravity showers can sometimes become air looked especially if someone has used a lot of water else where and the cold water storage tank has not had time to catch up. Did the plumber pull anything out of the pipe with the hoover?Depending on the shower, and locality of the mains feed you might beable to push cold water back up the hot supply pipe by putting the shower in the hot position and connecting a hose to the shower outlet this is not a good idea if your shower has non return valves though.