How water problem

[Mrast]

Hi all,

I have just had my bathroom refitted - part of this refit was a new bath.

The old bath had a mains fed thermostatic mixer shower valve and separate bath taps - i had no issue previously with this setup.

My new bathroom has done away with the separate bath taps and got a wall mounted thermostatic bath and shower mixer tap
Buy Premier Thermostatic Wall Mounted Square Bath Shower Mixer Tap Chrome Online

Since this has been put it the hot water goes cold for about 15 seconds every now and again.

My wife was just in the shower so i stood at watched the boiler..... this is what i saw..........

Boiler problem when shower on - YouTube


Further to this - i didnt catch it in the video but still with the shower on and hot, the demand on the boiler for hot water stops completely and left me with just a green power light - then it would fire back up about 20 seconds later and this is the point the shower water would go stone cold temporarily.

There is 22m copper going from the boiler up to the bathroom but somewhere under the bathroom floor it is then reduced to 15mm copper - and this 15 mm copper runs to the new taps (same pipe work for the old tap, just slightly altered to remove the branch offs for the old bath taps.)



Any body any idea what could be wrong please, or any suggestions on what i could check?

Not normal for the boiler to keep igniting every 25 secs or so like shown in the video surely?

Many Thanks in advance

 

[Mrast]

If you can get that shower for £80, you should! But I doubt you can tbh

Quite!! Was just the shower mixer for that price.

 

[Mrast]

Update:

This is what the supplier of the tap is saying when i complained of it being faulty

Hi,

It sounds as though the non-return valves may be sticking in the inlet on the tap, the customer could try taking the tap off and clearing /freeing the non-return valves if that does not work we would need to send new non-return valves.

Regards,


Does he mean the fitting things that came with the tap?

1 end is 15mm and screws into the compression elbow coming out the wall and the other end is 22mm that the actual tap screws into and it kinks in the middle? (sorry not sure what they are called and cant find a picture of them on google for love nor money)

 

[Irish]

If you've had the valve if the wall and the water is flowing through the pipe work for 10 minutes like you said ,then the non return valvesif fitted are not sticking

 

[Mrast]

If you've had the valve if the wall and the water is flowing through the pipe work for 10 minutes like you said ,then the non return valvesif fitted are not sticking

Yes with no tap on there is no problem.

I've followed the pipework and from the back of the tap both feeds run down the wall, then into an isolator each, then off to wherever they go to next through the ceiling.

I've goggled images of non return valves and i don't see any anywhere.

Or are they built into the mixer tap?

Am i right in thinking that because the cold water is a higher pressure than the hot water, that its going through the mixer valve and forcing its way back down the hot water pipe, thus causing the boiler to shut off??

When no tap is on, both feeds are separate again and have no way of contaminating each other hence why it works fine then?

 

[Masood]

If you've had the valve if the wall and the water is flowing through the pipe work for 10 minutes like you said ,then the non return valvesif fitted are not sticking

Not always the case - there may be no NRVs on the pipework itself, just the inbuilt ones in the shower mixer. I've had problems with Crosswater ones sticking a while back. They sent new ones out free of charge, but I think they may have had a dodgy batch.

 

[Irish]

Fair point masood I didn't read the company's reply properly

 

[Mrast]

Right - Sherlock has been to work this lunch time.

I checked the Non Return Valves on the tap inlet as instructed by the manufacturer and the hot was a little stiffer than the cold but they both opened and closed relativly ok.

Popped the tap back on:

Run the bath for 10 mins watching the boiler - no problem. hhhmmmm

Flicked the knob up for the shower - within 30 seconds the boiler was in its re-ignite process.

So took the shower head off and just had the water spurting out the shower hose....... no problem with boiler. (although i had to get the mrs to manually hold the shower knob up as it wouldnt stay without the shower head being on)

So this leaves 1 of 2 things to me....

Shower head is restricting flow too much and causing the pressure drops, thus boiler ignition issues.

The shower knob on the tap isnt opening fully compared to when manually pulled and held up

Im going to steal a few mates shower heads tonight and see what happens.

 

[Dotty]

Keep the one that works.......

 

[Mrast]

What will be the reason this one doesnt work?

Its the same head and hose that i used on the old shower mixer i had?

 

[Mike Jackson]

Possibly too restrictive.

 

[Mrast]

Tried 3 different heads including mine and the ignition behaviour is better on 2 of them but still happening - just less frequently than on mine.

On mine i removed a plastic noggin thing from the end of the shower head and this has increased pressure from the shower massivly - didnt sort out the igniton issue though.

On 1 of them aswell i had to hold the shower knob up for about 10 seconds before it would stay up and not revert to sending water through the tap filler.

Also noticed tonight that if i only turn the tap pressure dial half way then the boiler behaves the same way - only when the dial turned on full does the boiler not play up.

Dont know what this proves wither but while the shower is on if i open up another hot water tap full blast it cuts the shower off and sends the water out the bath filler instead.

Think im just going to return the tap as faulty.

It clearly isnt right.

Agreed?

 

[Howsie]

Either that or poorly designed.

 

[Mrast]

Update:

P.O.S tap is being collected Monday to go back to the company for a refund.

I have plumped for a Grohe Essence Single Lever Bath Shower Mixer from a local supplier.

Fingers X'd

 

[Howsie]

Right choice IMHO.