Shower Problem

Robbie_Duck

Im after help again!

We recently had a thermostatic mixer shower fitted.
http://cgi.ebay.co.uk/THERMOSTATIC-2-WAY-ROUND-MIXER-SHOWER-VALVE-TAP-W87_W0QQitemZ330335514277QQcmdZViewItemQQimsxZ20090605?IMSfp=TL090605169002r5556

Looks really good but doesn’t always work!

Occasionally when we turn it on nothing happens.

It’s a gravity fed system via a salamander pump.

Originally we thought it was an air lock but have had a plumber out and he cant see anything wrong with the pipe work. There’s plenty of fall on it.

We can get it working again by releasing one of the valves on the top of the pump and then the pump kicks in and it works fine for a day or so but then the problem re occurs.

Tried swapping the pump for a new on but the same problem occurs. Although we can get round it in a slightly different way by turning the temperature control to cold and it stutters into action.

Have asked about and have a couple of theories:

It’s a faulty thermostat in the shower. I hope not this would mean removing all the tiles to get at the shower unit.

The hot water supply is too hot. The Salamander instructions does recommend putting some sort of temperature regulator on the hot pipe before it gets to the pump if the hot water exceeds 60c. The hot water does come through quite hot so this might be a solution.

Any one got any other suggestions?!

Thanks in advance!

andyhop

Robbie_Duck wrote: »

Im after help again!

We recently had a thermostatic mixer shower fitted.
http://cgi.ebay.co.uk/THERMOSTATIC-2-WAY-ROUND-MIXER-SHOWER-VALVE-TAP-W87_W0QQitemZ330335514277QQcmdZViewItemQQimsxZ20090605?IMSfp=TL090605169002r5556

Looks really good but doesn’t always work!

Occasionally when we turn it on nothing happens.

It’s a gravity fed system via a salamander pump.

Originally we thought it was an air lock but have had a plumber out and he cant see anything wrong with the pipe work. There’s plenty of fall on it.

We can get it working again by releasing one of the valves on the top of the pump and then the pump kicks in and it works fine for a day or so but then the problem re occurs.

Tried swapping the pump for a new on but the same problem occurs. Although we can get round it in a slightly different way by turning the temperature control to cold and it stutters into action.

Have asked about and have a couple of theories:

It’s a faulty thermostat in the shower. I hope not this would mean removing all the tiles to get at the shower unit.

The hot water supply is too hot. The Salamander instructions does recommend putting some sort of temperature regulator on the hot pipe before it gets to the pump if the hot water exceeds 60c. The hot water does come through quite hot so this might be a solution.

Any one got any other suggestions?!

Thanks in advance!

Is the shower piped correctly?Hot to Hot, Cold to Cold?

Where is the water tank in relation to the shower head.Is the shower head above the tank. You may require a negative head pump?

Does the pump have its own dedicated supply from the hot water cylinder and from the cold water storage tank?

Robbie_Duck

Is the shower piped correctly?Hot to Hot, Cold to Cold?

Where is the water tank in relation to the shower head.Is the shower head above the tank. You may require a negative head pump?

Does the pump have its own dedicated supply from the hot water cylinder and from the cold water storage tank?

Hi, thanks for looking.

Definitely piped correctly. Checked it and checked again and checked again!

Water tank is on a raised stand in the loft. Pump is on the loft floor (1.5m fall between tank and pump). Shower head below that (~1.5m fall between pump and shower unit).

Yes. Pump has its own feed from the hot water cylinder and the cold water tank.

mikey72

Do you have an anti gravity loop in the hot water feed, where it comes out of the cylinder? NRV in the hot outlet as well?

RUSH2000

Came across this same problem only yesterday. Installation was exactly to pump manufacturers recommendations but behaved as you discribed.

Traced problem to the inline NRV fitted to pump outlet hot side. This was sticking, preventing gravity flow to shower valve when set in normal 38deg position. Moving thermostat towards cold opened flow path allowing pump cold side flow switch to start pump.

Try different NRV, maybe gravity type or with lighter spring (could try removing the spring from existing)

You can confirm if NRV is problem by opening air bleed valve that should be fitted above it. If no water comes out NRV isn't opening.