Any plumbers in the house?

I have a problem which is a little strange.

we have an en suite in our bedroom and also a family bathroom on the same 1st floor. Our ES shower works perfectly fine but the bathroom shower runs cold despite being set on hot. However, if we run the cold tap in the bathroom sink, or the bath tap at the same time then it runs at a useable temperature.

this is not confined to just us, one of our neighbours suggested it as it worked with them. We're in a small close of 4 newish (5yrs old) houses, so a little strange.

its been suggested that it maybe the mains pressure, but this situation has only just started (well about 3mths), which suggests to me that it maybe a shower problem. However, since the shower chucks out hot water when the taps on then may be not

the shower is in the bath but at the other end to the bath taps. The taps seem to be at a reasonable pressure and the hot tap is bloody hot!!! The shower also runs hot when the bath cold tap is running.

Apologies if ive not explained this properly but does anyone have any ideas?

Pete

What's an ES shower?

It's the shower in the En-Suite.

I think we need to know more. Is the shower electric & how is the bathwater heated?

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Originally Posted by jwg663

It's the shower in the En-Suite.

I think we need to know more. Is the shower electric & how is the bathwater heated?

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Doh!

Its heated by a boiler (its not an electric shower) and I assume its using the mains pressure to get it upstairs! I've never been into the very small loft space but I don't think there is a water tank.

would that be right?

Pete

Do you have a combo boiler or a hot water tank in the airing cupboard?

If you've a tank in the airin cupboard then you've too much mains pressure so the cold water is at a higher pressure than the hot. Running the cold tap reduces the pressure to the shower allowing a more equal flow of hot and cold water through the shower.

It might help to close the cold water mains stop valve as much as you can without reducing the flow too much. This will reduce the cold water pressure without having to run the cold tap.

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Originally Posted by badger1

Its heated by a boiler (its not an electric shower) and I assume its using the mains pressure to get it upstairs! I've never been into the very small loft space but I don't think there is a water tank.

would that be right?

Pete

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Is it a combi boiler pete? When you turn a hot water tap on with a combi it should fire up when it detects a flow. If that is the case does the boiler fire up when you turn the shower on?

It's a combi and it does fire up when the shower is on. No tank, and no airing cupboard

I'll try and reduce the mains stop cock and see if that helps.

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Originally Posted by badger1

It's a combi and it does fire up when the shower is on. No tank, and no airing cupboard

I'll try and reduce the mains stop cock and see if that helps.

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I'd be surprised if it does, if the boiler fires up when you turn on the shower then it has detected the flow to the shower. Try turning on a hot tap in the on-suite until it flows constant hot then turn it off and immediately turn on the shower, it should run hot within seconds. Let us know what happens.

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Originally Posted by Daz

I'd be surprised if it does, if the boiler fires up when you turn on the shower then it has detected the flow to the shower. Try turning on a hot tap in the on-suite until it flows constant hot then turn it off and immediately turn on the shower, it should run hot within seconds. Let us know what happens.

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just tried that - shower was cold, then very slightly warm (maybe 5secs) then cold again

If its a combi, turning down the pressure won't help because both hot and cold are st the same pressure already.

As Daz said, the boiler's possibly not detecting the flow so not firing up.

It may be a stupid question but have you got the hot and cold pipes connected to the correct ports on the shower?

The mixer on the shower could be faulty. The hot and cold mixer [ not sure if that's the correct term ] that governs the water temp could be sticking or broken on the shower.

If no quick fix, then NHBC might cover getting it looked at and fixed if house is under 10 years old and can be seen as a build issue if your neighbour has the same problem?

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Originally Posted by Dave+63

If its a combi, turning down the pressure won't help because both hot and cold are st the same pressure already.

As Daz said, the boiler's possibly not detecting the flow so not firing up.

It may be a stupid question but have you got the hot and cold pipes connected to the correct ports on the shower?

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I would assume so as it has been working properly - it's only recently that we've noticed the problem.

You could try either taking the shower off the wall or disasembling it as mine had little strainers and the hot was blocked with scale meaning had to keep turning the temp up to get a warm shower so perhaps this is restricting the supply of hot & the 2nd tap drops the cold supply and so balances the shower.

Maybe see how quickly you can fill a bucket from the cold tap in the kitchen to see what flow you have as I had little flow + a scaled up combi & was hopeless ?

The "bar" showers come off with 2 big nuts at the back (just turn off the stopcock first) the mira one I had I found the instructions for on-line.

From what you have described Pete your boiler probably needs a replacement water valve. Get somebody in to check it.

Cheers guys for all your help. Looks like I need to get a man in!!

Sounds to me that the hot and cold supplies to the shower are crossed. The easy way to check is run the shower and touch the inlet connections to see which side heats up, the hot should be on the left.

Had this once before and the water pressure was the cause.

The pressure from the cold side of the mixer was so great that it was inhibiting the flow of the hot water. A reducing valve on the cold side fixed it. Downside was that when another tap or the WC was being filled, it got dangerously hot!

Could be that the pump being used for the shower is not up to the job?, or on its way out, which is then not providing enough pressure.

Get someone in...its all going to be conjecture until someone physically tests it.

HTH