Plumbing Advice Needed - Trickling tap...

Beverley75

Good evening all, 

A plumber came around and replaced both ceramic washers for my kitchen mixer tap. 

Ever since then my hot water comes out of the tap at a trickle and takes ages to heat up (the cold water tap is fine) 

He came back out but shrugged his shoulders and said he doesn't know what happened and couldn't fix it. 

I'll try to attach a pic of the tap and washers, but any plumbers who can offer some advice would be greatly appreciated - I am really NOT good at DIY! 

Beverley75

Image of tap style and washers:

ThisIsWeird

Does the hot tap turn smoothly and through 90 degrees, just like the cold one? If so, almost certainly the actual new valve is working fine.

So that would leave an issue with the hot water supply to the tap.

I'm assuming you don't have either a combi boiler, or an 'unvented' hot cylinder, but instead a 'normal' vented hot tank? In which case, chances are you have an air lock from the work.

Anyhoo, if you could confirm, please?

Beverley75

ThisIsWeird said:

Does the hot tap turn smoothly and through 90 degrees, just like the cold one? If so, almost certainly the actual new valve is working fine.

So that would leave an issue with the hot water supply to the tap.

I'm assuming you don't have either a combi boiler, or an 'unvented' hot cylinder, but instead a 'normal' vented hot tank? In which case, chances are you have an air lock from the work.

Anyhoo, if you could confirm, please?

Hi! 

Thank you so much for replying! 

I have a combi boiler - and the new tap turns smoothly 90° as it ever did.

(and apologies for the delay in replying; I didn't receive my usual email alert) 

ThisIsWeird

Beverley75 said:

Hi! 

Thank you so much for replying! 

I have a combi boiler - and the new tap turns smoothly 90° as it ever did.

(and apologies for the delay in replying; I didn't receive my usual email alert) 

No problem. About the 'late' reply - which it wasn't anyway. :-)

But, being a combi, the most obvious cause - an air lock - is out the window :-(

Weird that the plumber couldn't suss the cause. Any idea what he tried, other than scratchinhg his head?

Ok, being a combi, every tap in your home - hot and cold - should be flowing at roughly the same, strong, rate ('strong' - assuming your mains water pressure is ok). So, what are your other hot taps like? Flowing perfectly ok? The same as before?

If so, that rules out an issue at the boiler such as a blocked inlet filter, or a not-fully-reopened inlet valve following this work. So please report back on the other hot tap flows.

Do you know how the plumber approached this cartridge-replacing task? Did he turn off ALL the water, hot and cold, by shutting off the mains stopcock? Or, do you have isolating valves on the H&C pipes to the kitchen tap, so he only had to shut these off? Again, the answers to these will hopefully help point to where the issue 'must' still be.

Beverley75

ThisIsWeird said:

Beverley75 said:

Hi! 

Thank you so much for replying! 

I have a combi boiler - and the new tap turns smoothly 90° as it ever did.

(and apologies for the delay in replying; I didn't receive my usual email alert) 

No problem. About the 'late' reply - which it wasn't anyway. :-)

But, being a combi, the most obvious cause - an air lock - is out the window :-(

Weird that the plumber couldn't suss the cause. Any idea what he tried, other than scratchinhg his head?

Ok, being a combi, every tap in your home - hot and cold - should be flowing at roughly the same, strong, rate ('strong' - assuming your mains water pressure is ok). So, what are your other hot taps like? Flowing perfectly ok? The same as before?

If so, that rules out an issue at the boiler such as a blocked inlet filter, or a not-fully-reopened inlet valve following this work. So please report back on the other hot tap flows.

Do you know how the plumber approached this cartridge-replacing task? Did he turn off ALL the water, hot and cold, by shutting off the mains stopcock? Or, do you have isolating valves on the H&C pipes to the kitchen tap, so he only had to shut these off? Again, the answers to these will hopefully help point to where the issue 'must' still be.

He shut off the stopcock - and shut off all of the water. 

As far as I know, when he came back he tried replacing the new washer with another identical one (to no effect obviously) - and that was it.

All the other hot taps upstairs (dink & bath) are flowing fine - but I've been told the taps upstairs, unusually, are also running off the main water supply so are also potable, if that's any use 

ThisIsWeird

Beverley75 said:

ThisIsWeird said:

He shut off the stopcock - and shut off all of the water. 

As far as I know, when he came back he tried replacing the new washer with another identical one (to no effect obviously) - and that was it.

All the other hot taps upstairs (dink & bath) are flowing fine - but I've been told the taps upstairs, unusually, are also running off the main water supply so are also potable, if that's any use 

"I've been told the taps upstairs, unusually, are also running off the main water supply so are also potable". Yes, that's typcial of a combi system. There is no water 'stored' anywhere, so both hot and cold supplies are coming direct from the mains, the hot obviously being 'instantly' heated by the boiler as required. One of the main benefits of a combi system is that all the taps and outlets are mains-powered, so usually at a good flow. And all taps are potable, tho' you wouldn't usually drink from the hot...

Thanks for the other info. He only used the mains stopcock, so that rules out a partially-closed isolating valve. He replaced the cartridge, so that almost certainly rules out a faulty valve.

Through a process of elimination, that leaves only one thing. I lie, that leaves nothing - I haven't a scooby what's going on :-(

Ok, could you trace the pipes that supply the tap as far as you can, starting from under the sink? Just in the remote chance that there is an isolating valve that he may have seen and started to close off, before then going 'mains stopcock'. Other than that. I'm really stuck.

To investigate the cause further will likely require testing that the actual tap is receiving a good flow. An obvious - but potentially messy - way would be to remove the cartridge again, and turn on the water supply - see how wet your kitchen gets.

Beverley75

ThisIsWeird 

Ok, could you trace the pipes that supply the tap as far as you can, starting from under the sink? Just in the remote chance that there is an isolating valve that he may have seen and started to close off, before then going 'mains stopcock'. 

I'll give this a go later tonight when I'm home. 

I do vaguely remember seeing 2 little tap lever things when the washing machine (right next to the sink) was being installed??

I could be misremembering but I'm sure it's under the sink somewhere.

I'll have a proper look/feel around later. 

Thank you for trying, and I'll update you later, if that's okay 

ThisIsWeird

If they have plastic levers on them - one red and one blue - these are likely to be w/m valves. But take photos to show them.

An 'isolating' valve looks just like these, but without the plastic lever - usually it has a screwdriver slot.

Beverley75

Okay, so here's what I could see behind the cupboard under the sink:

1) A blue lever thingy (Technical speak) - no red lever though so goodness knows what it does... 

2) The stopcock tap

3) Two silver bolt/screw looking doodads (also Technical speak 😉), on the ancient pipework 

(sorry, had to upload images as a collage to condense) 

ThisIsWeird

Good info.

The yellow cap is, I am assuming, a cap, and is used to cap-off an unused valve so it doesn't drip when not in use. I take it there's nothing coming out t'top of this yellow cap? In which case you can ignore it - until you want to fit a cold-feed washing machine or dish washer.