Odd pumped shower problem.

[pieceofmind]

Not long moved into a new house. It has an old gravity fed water system. There are 2 showers upstairs, both running from a pump in the airing cupboard. One works perfectly and the other will not hold its temperature for love nor money. I assumed (wrongly it seems) that because one was fine that the fault with the other one must be the thermostatic valve in the shower mixer. Because it was fairly cheap (and an easy bolt on job) I simply bought a new shower with the same fitting and connected it up. However it's exactly the same as the old one - temperature all over the place, a tiny movement of the lever results in a massive change in temperature etc. Can anyone point me in the direction of what the issue might be?

Cheers

 

[flameport]

Hot and cold inlets to the shower are the wrong way round.

 

[pieceofmind]

Alright, thank you for the quick response! I'll swap them over at the weekend. There is flexible plastic 'JG Speedfit' style pipework in the loft joined to the chrome pipes that appear through the ceiling in the bathroom and go to the shower. Hopefully I should be able to disconnect and reconnect those without any new parts. Can anyone confirm this either way?

Cheers

 

[flameport]

Theoretically they can be removed and put back on the pipes.
Speedfit onto chrome pipes is somewhat dubious, the proper method is to remove the chrome plating where the fitting connects.

 

[pieceofmind]

OK thanks. I'll make sure I start early then to give me time to go to the shops if it fails! Many thanks for taking the time to answer this for me - the shower was driving me nuts and had my wife complaining daily, so it's very much appreciated,

 

[cross thread]

before swaping pipes run the shower on its hottest setting and feel the pipe .hot is normally on the left

 

[pieceofmind]

The hot pipe is the one on the left. Does that mean that reversed pipes is not the issue? If they still need to be swapped there are 2 places I could do it, one being a plastic to plastic join, and the other being plastic to metal. I've attached pictures of both for clarification. Which would be quickest/easiest/least likely to leak later on?

Cheers!

 

[pieceofmind]

Anyone know the answer to this?

 

[JohnD]

On the left when you're facing (using) the tap or mixer, that is.

If the mixer is fitted upside down, as sometimes happens, its inlets will be the wrong way round.

You do mean that both hot and cold suppplies come from the loft tank, at low pressure before being pumped? The cold doesn't come off the (high pressure) watermain supply?

 

[pieceofmind]

Yep, as I stand looking at the shower the left hand pipe is the hot and the right is cold. Does that mean I shouldn't swap the pipes over and that something else is causing the temperature fluctuation?

 

[oldbuffer]

1. If the shower bar has been fitted upside down, this would have the same effect as connecting hot to cold and vice versa.
2. If they are the same shower in each room, are they mounted the same way up?
3. Otherwise, if the hot pipe is correctly fitted to the hot in side of the shower, the problem lies elsewhere.
4. First point to check would be any filters and / or non-return valves fitted to the outlets from the wall.
5. Photo's of both showers would be useful.

 

[JohnD]

I edited my post while you were replying, with another thought.

 

[pieceofmind]

On the left when you're facing (using) the tap or mixer, that is.

If the mixer is fitted upside down, as sometimes happens, its inlets will be the wrong way round.

You do mean that both hot and cold suppplies come from the loft tank, at low pressure before being pumped? The cold doesn't come off the (high pressure) watermain supply?

I'll have to get up into the loft to double check but as far as I recall the hot is pumped (the pump is situation next to the hot water cylinder) but the cold is supplied by a tank in the loft (mains goes to the tank and gravity brings it from the tank to the two showers).

 

[pieceofmind]

1. If the shower bar has been fitted upside down, this would have the same effect as connecting hot to cold and vice versa.
2. If they are the same shower in each room, are they mounted the same way up?
3. Otherwise, if the hot pipe is correctly fitted to the hot in side of the shower, the problem lies elsewhere.
4. First point to check would be any filters and / or non-return valves fitted to the outlets from the wall.
5. Photo's of both showers would be useful.

They are 2 completely different showers unfortunately. I will take photos of both anyway though. There are no inline filters or valves. Back ASAP with pics...

 

[JohnD]

I'll have to get up into the loft to double check but as far as I recall the hot is pumped (the pump is situation next to the hot water cylinder) but the cold is supplied by a tank in the loft (mains goes to the tank and gravity brings it from the tank to the two showers).

*Beep beep*

Do you mean that the hot and the cold are at different pressures?

That would (does) cause it.