Shower not getting hot

[Mark Wright]

Hi, I'm a fairly regular on the electricians forum but know nothing! about plumbing.

Basically all other taps get hot but the shower is luke warm. It's not mine but belongs to a little old lady. She had it replaced lately and I don't have the heart to tell her its not fixed. It's a bar-type shower.
It's not an electric shower.

There have been various problems but I think it might have been like this since she had a new boiler put in but I'm not sure.

Please can anyone give any advice or recommend a good and honest plumber in Surrey. Like I said on ectriciansforums.net I assume a good plumber could figure out the problem in minutes.

 

[Deleted member 120897]

Could be crossed pipe(s)/passing valve. Is the boiler a combi?

 

[Mark Wright]

I believe its a gravity system

 

[Deleted member 120897]

I believe its a gravity system

If it’s gravity, could be incorrect pressure/unbalanced supplies, or fitted wrong.

 

[Mark Wright]

The last shower had the same problem I think. Are any of the problems in keeping with a new boiler?
and thankyou for your replies.

 

[Deleted member 120897]

Unbalanced supplies would be the same if a new boiler fitted, unless a combi was fitted (as the supplies would almost be equal).

 

[Mark Wright]

I think it's a Low pressure gravity system but I might be talking out my bottom. But the sink tap about a meter away gets boiling hot.

 

[Mark Wright]

If I took it of the wall and sorry if this is stupid to you guys I would have a cold and a hot pipe is that correct?
and If I turned the water on the hot should be coming out boiling hot is that correct? and I could also check the pressure?

 

[Deleted member 120897]

Yes, there should be 2 pipes, hot and cold. It might be that they’re reversed too, eg, shower hot to cold pipe and vice versa. Yes you should get hot water from the hot, not boiling. You could check the pressure of both too.

 

[Mark Wright]

Thanks agian for your reply. I should get hot water from the hot pipe the same heat as the max heat the sink tap can provide is that correct?

 

[John.g]

Maybe, without taking if off the wall, isolate the cold water then turn on the shower, you should get hot water until it reaches the shower set temperature of ~ 35/40c, then the flow of water should stop completely. (assuming a thermostatic shower).

 

[Mark Wright]

Maybe, without taking if off the wall, isolate the cold water then turn on the shower, you should get hot water until it reaches the shower set temperature of ~ 35/40c, then the flow of water should stop completely. (assuming a thermostatic shower).

What a good idea.