Plumbing Question - Shower not hot

[brianmoooore]

Reason i am confused is that there is talk of the shower take off from the cylinder being lower than the top take off and there is talk of the pump running when either tap or shower are running.

There's a Suffolk flange fitted, so the shower hot water comes from about three inches lower down the cylinder than the rest of the hot water. This shouldn't make any difference to comparative water temperatures until the hot water is nearly all used up.
It would be very unusual to feed downstairs taps from the same pump that feeds the shower, but not impossible.

 

[plugsandsparks]

OK so maybe impeller has fell off, could try turning pump off and running shower to see if it is exactly the same?

 

[mainline]

I wonder how the OP is getting on.
It's always nice to have an update on the outcome.

 

[Mark Wright]

I wonder how the OP is getting on.
It's always nice to have an update on the outcome.

I hate that when they just disappear
Sorry, as you know I turned the thermostat up on the tank and yes it is warmer but it's not right and I do feel this has led me in the right direction because I did feel it wasn't right from when the boiler was changed.


I would like to get a thermometer suitable to measure the temp if anyone could recommend one?

Another thing if I quickly turn the temp right down and right up it is hot for like a second.

Also this has made me what to learn S and Y plan etc I've been putting it off - I'll probably start another thread at some point.

But I'll say it again this is a great forum with some really helpful people.
Mark.

 

[Mike Johnson]

I think the problem may be the shower mixing valve is designed for mains pressure and the OP has only tank gravity pressure, or the pump may be caput and will not operate correctly with the pressure now available with the new boiler, which again may be designed for mains pressure and only has gravity pressure, both need checking, whatever is causing the problem seems to be a disparity between the boiler, shower pump and tank pressure differentials.

The lack of gravity pressure equipment is a continuing problem for older house's and installations.

 

[brianmoooore]

I think the problem may be the shower mixing valve is designed for mains pressure and the OP has only tank gravity pressure, or the pump may be caput and will not operate correctly with the pressure now available with the new boiler, which again may be designed for mains pressure and only has gravity pressure, both need checking, whatever is causing the problem seems to be a disparity between the boiler, shower pump and tank pressure differentials.

The lack of gravity pressure equipment is a continuing problem for older house's and installations.

The shower valve in question is designed for a minimum pressure of 0.4 bar.
It is fed from a purpose designed shower pump which should be capable of providing a pressure of 1.5 bar - 3.0 bar, depending on the exact model, so it should work properly.
The design and layout of all the plumbing we can see in the pics is OK, although a little odd in places.
There's something that has failed, is not set up properly, or is partially blocked.
I'm still unclear if the shower worked properly when the water was heated by electricity, or was just 'better'.

 

[Mike Johnson]

Ten pages of going around in circles eventually we will disappear up the shower head, seems to stem from the replacement of the shower mixer and boiler at the same time?

 

[LukeD]

This is so simple..... get the temp of the hot water tested as close before the mixer as possible . If its as hot as expected .Buy a new mixer ..... !

 

[Mark Wright]

This is so simple..... get the temp of the hot water tested as close before the mixer as possible . If its as hot as expected .Buy a new mixer ..... !

It's a brand new shower.

 

[Mark Wright]

Anyway like I said I feel I've been put on the right track - for some reason the water entering the pump isn't very hot, unless I use the Immersion. I think I'll measure the temp(i.need a thermometer) and just go to the company that fitted and say look this is the temp here's what I found, fix it.

 

[Mike Johnson]

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[mainline]

Anyway like I said I feel I've been put on the right track - for some reason the water entering the pump isn't very hot, unless I use the Immersion. I think I'll measure the temp(i.need a thermometer) and just go to the company that fitted and say look this is the temp here's what I found, fix it.

Have you tried turning your tank stat and boiler temp up ?
The tap hot water temperature is going to be the same as the immersion tank

 

[Mike Johnson]

I have in the past cured a very strange temperature difference by turning on all the taps in the bathroom, seems that if I have been working on the plumbing I sometimes get an air lock and this cures it, have you tried running the shower without the thermostat in place for a while and then carefully testing the water temperature?

 

[Mike Johnson]

Have you tried turning your tank stat and boiler temp up ?
The tap hot water temperature is going to be the same as the immersion tank

He has hot water at the taps, it's just not hot at the shower pump.

That gives me a thought (lonely I know) is there a temperature compensator fitted on the flow to the shower, one that mix's hot and cold water? something like this: Water Valve Control Pipe Replace Supplies Tap Temperature Thermostatic | eBay - https://www.ebay.co.uk/itm/285144708639?

 

[mainline]

The only thermostatic mixer is going to be in the shower mixer bar
He could just fit a mixer that’s not temperature controlled