Poor hot water from shower mixer tap...

[Newgate_Blue]

Hi all,

Hope there is someone who can help me with this.

Bathroom installed a couple of years ago with new shower mixer tap. We have noticed that the water pressure from the hot tap has been reducing until now it is just a trickle!

Water comes from a Combi boiler.

Have read some earlier posts and suggestions saying that similar problems have been airlocks.

Suggestions welcome!

Thanks

 

[Newgate_Blue]

The Boiler is a Worcester 35CDi, if this helps!

 

[Al-Glasgow]

It could be the flow restrictor (if your boiler has one).

Or the diverter valve.

Are all of your hot taps in kitchen/bathroom slow flow on hot ?.

Alan

 

[Newgate_Blue]

Alan,

All the other taps in the house flow ok, including another shower in an en-suite room.

 

[Al-Glasgow]

So the only poor hot flow is from the hot bath/mixer tap ?.

 

[Newgate_Blue]

Yep, that's right!

 

[Al-Glasgow]

Well in that case a simpler problem with the mixer tap exists.

can you measure the flow rate using a jug, compare it to another hot tap, time it over a minute.

Maybe some debris is lodged in the tap unit.

Al

 

[Newgate_Blue]

Debris is quite possible - i'll check this tonight.

Do you think using the method used to clear an airlock will help this?

 

[Al-Glasgow]

Debris is quite possible - i'll check this tonight.

Do you think using the method used to clear an airlock will help this?

It may well do, im unsure, maybe a pro can confirm this.

Alan

 

[Newgate_Blue]

Al,

Thanks for your help - i'll let you know how I get on!

 

[Newgate_Blue]

Hi,

Just tried blocking spout and turning on hot then cold tap - this has not worked!

I've noticed that the tap does not turn fully on - it is difficult to fully turn and I can only get about a 1/4 turn when it should turn all the way around.

Do you think this could be the washer?

 

[Al-Glasgow]

Did you run a piece of hosing from hot to cold, then turn on cold water ?.

Does the cold tap turn more than the hot ?.

Al

 

[ChrisR]

Your HW is mains pressure as its through a combi. You simply don't ever get airlocks on mains fed pipes. (well almost - not in your case!)

It'll be something like scale jamming things up, a dead thermostatic cartridge, "spread" washer stopping the water going by. Just possibly its scale in the shower head - though at first thought that would seem impossible, there are reasons..

You mentioned not being able to turn the tap, so I assume it's not a thermostatic type...? Take it apart, clean with limescale remover and grease with silicone grease, and a new washer.

 

[Newgate_Blue]

Thanks ChrisR,

I'll try the dismantling process - which I expect will cure the problem.

Thanks for all your help.

 

[Newgate_Blue]

Success! I didn't even have to strip the tap down.

'Er indoors managed to turn the tap all the way (after a struggle) and now the flow is working and the tap turns freely!

Brute force triumphs!