No hot water in power shower

[KenMaz]

Hi,

I have a power shower which isn't delivering hot water or even warm water. Turning the knob on the shower to hotter makes no difference to the water temp, which stays at cold. I'm a noob when it comes to diy, so forgive my lack of knowledge.

My system is like the diagram on bottom right of www.showerdoctor.com

The pipe from the top of the hot water cylinder (shown as 6) is hot at the top (where it leaves the tank) and becomes lukewarm to nearer the pump. However the last six inches of the hot water inlet to the pump is very hot to touch, and the side of the pump is practically too hot to touch. Similarly, the first six inches of warm pipe out (towards shower) is hot to touch. It almost seems like the pump is running dry and the heat generated is from this, and not from hot hot water.

I should add that there's another power shower (different model) in the ensuite bathroom (being pumped from a separate pump also in the hotpress cupboard) and its works perfectly. Also, the pwoer shower which isn't working properly is very rarely used, and this problem only came to light when we tried to use it when the ensuite bathroom was being redecorated and out of use.

Any suggestions which I could try ?

Thanks.

 

[ChrisR]

I'd think you're right.
You HAVE HAVE HAVE to prime the pipes and pump before you put the pump on, or you'll wreck it. May be too late.
Disconnect the pipe from the pump inlet to check, then outlet- water should come out. Water should flow through the pump even when it's switched off.

If it doesn't, you've got an airlock, a blockage, or the valve isn't working.

 

[KenMaz]

I'd think you're right.
You HAVE HAVE HAVE to prime the pipes and pump before you put the pump on, or you'll wreck it. May be too late.
Disconnect the pipe from the pump inlet to check, then outlet- water should come out. Water should flow through the pump even when it's switched off.

If it doesn't, you've got an airlock, a blockage, or the valve isn't working.

Thanks Chris, I'll check that out. If necessary, how do I prime the pipes and pumps?

 

[denheat]

Its quite possible that the wax capsul which determines how much water passes through the valve could be faulty.
If it is then the a new capsul will have to be fitted. This is normally the problem if you cannot get hot water.

 

[KenMaz]

Further update ... I had a plumber mate look at the problem and he took apart the pump and found that a switch on the hot water pipe is faulty. He spoke to a plumbing supplier and they quoted £75+vat this, which seems excessive for such an insignificant part!

I've taken a photo of it and this can be seen at the link below. There's an identical one on the cold water pipe too.

There's no name or part number on this. Can anyone tell me what this is called (part number?), how much it costs or where I can buy on online? The pump is a Monsoon 102T.

http://i80.photobucket.com/albums/j189/frankiem_bucket/switch.jpg

Thanks.