What's wrong with this Thermostatic shower?

[meganfurley]

Hi,
I have a recently replaced Thermostatic Shower which was fine for about a month but now takes forever to get a flow going. The shower sometimes becomes better after letting it flow for five minutes (even keeping the shower head down to the shower tray) and at times even that does not help.

The Boiler is a conventional boiler with a low power but prior to this the shower was pretty good and even the new one worked well for a month.

I have tested making sure other pipes aren't being used.The hose pipe and shower head are fine but the inflow itself is very weak. Could some washer or something have slipped or anything that you can suggest.

The link for the make of the shower - Triton Exe Thermostatic Bar Shower Mixer (https://www.victorianplumbing.co.uk/triton-exe-thermostatic-bar-shower-mixer-kit-unexthbm)

Any suggestions welcome. Megan

 

[morph100]

Ive got a similar problem but mine runs fine until you turn the pressure up and then it cuts out to nothing, I did the same as you and checked all the other taps etc were off, I also took my boiler out of eco mode and tried just running cold water but it was still the same, so you could try those to see how it reacts? My thread is here https://www.diynot.com/diy/threads/shower-cuts-out-when-on-full-power.491091/ hopefully between us and with the friendly folk here we can troubleshoot our issues

 

[meganfurley]

[QUOTE="morph100, post: 4015402, sues [/QUOTE]

Thanks. In my case, at times it even works alright! I am just lost

 

[terryplumb]

The hot and cold Inlet ports contain filters ,and non return valves. You should check that the filters are clean and free from any obstruction. Also check that the non return valves are not sticking. This shower valve requires a minimum working pressure ,and if you have a gravity fed hot and cold going to the valve its possibly not enough. Is your hot water from a storage cylinder and do you have a cold water storage cistern ,usually in the loft. Is the shower upstairs or downstairs ??

 

[meganfurley]

[QUOTE="terryinimum working pressure ,and if you have a gravity fed hot and cold going to the valve its possibly not enough. Is your hot water from a storage cylinder and do you have a cold water storage cistern ,usually in the loft. Is the shower upstairs or downstairs ??[/QUOTE]

Thanks terryplumb

It's a gravity fed system as you described.The shower is upstairs. The shower descrpn. on the website said it would suit low pressure systems with pressure from 0.1 bar min to 5.0 bar max.

You know the old thermostatic shower was excellent.We needed to redecorate and still I cannot fault it very much for the first 5 weeks. What I cannot understand is why it has suddenly dropped pressure. When I remove the hose I can see that the inflow is weak for a long time before it builds up.

Is it a big job from a plumber? Was hoping to avoid big spending

 

[terryplumb]

If you remove the hose ,at the shower valve end, and turn shower on cold only, take a note of the flow of water coming out.then turn to hottest setting ,and again note what the flow is like. They should be very similar .the valve needs minimum 0.1 bar pressure in order to work adequately. That equates to a height difference between the shower head and the bottom of the cold water storage tank in the loft.( measured vertically ) of approximately ,1 metre. So when your shower head is mounted on the wall ,probably a couple of feet below the ceiling ,the loft tank in the attic would be just above. So you are probably borderline minimum pressure.however you said it worked OK for a few weeks ,so something has changed. And I would refer you to my first post on things to check ,which is within the scope of most keen diy'ers who have tools and the confidence to have a go. It involves turning off the water supplies to shower ,undoing the two big nuts that hold the shower valve to the pipework , which you then withdraw from the wall. the filters are then visible for inspection ,and the non return valves are just below them. Of course you could call in a plumber ,but it is really easy to do the above.

 

[meganfurley]

[QUOTE="terryplumb, post: 4015587, member: 2lies to shower ,undoing the two big nuts that hold the shower valve to the pipework , which you then withdraw from the wall. the filters are then visible for inspection ,and the non return valves are just below them. Of course you could call in a plumber ,but it is really easy to do the above.[/QUOTE]

Thanks terryplumb

I'll try and do that. I have checked what you suggested. The cold water pressure is very good; it is the hot water which is lacking. The warmer I try the more I struggle for pressure!
What does it mean? Can it be sorted considering it was doing well for some time.

 

[terryplumb]

OK ,so you have narrowed it down to the hot supply ,which I think enters the valve on the left side ,as you look at it from the shower side. I assume all other hot taps in the property work perfectly normally ,if so that would tend to rule out any air lock issue. You should check that the water level in the loft tank is good, at least 2/3 RDS full. Then trace the hot pipework from the shower ,looking for isolation valves to ensure ,if you have any ,that they are fully open and not restricting the flow. After making these checks ,you can then go to the removal of valve to check the filters. One final question for you....is the cold to the shower by any chance directly from the mains supply ? It shouldn't be !! You can establish this by turning off your mains stopcock ,and see if shower still runs cold water out. If it does not its mains fed cold. If it runs fine its from the loft tank.