Hot water fault

[hammers4spanner]

Hi all ,

Got a job that has a reoccurring blockage on the hot side to sink tap only, system is cylinder with cwst in loft space. Initially owner thought they had a faulty tap and changed it no water came out but sucked through with wet vac.
Ran it for 5 mins after and all worked fine, later today had a call same cust kitchen tap has stopped again, went out just a drip from hot tap again.Speedfit under sink so pulled apart fitting and nothing but a drip so its defo not the tap. They have a hot tap in basement which works fine , hot tap in cloakroom toilet works fine which is on same floor as this tap ,and main bathroom toilets hot taps work fine.

what do you guys think ?

 

[ShaunCorbs]

Sounds like an air lock have you tried once cleared runing for a good 5-10 mins ?

 

[quality]

sounds airlocked to me connect cold to hot and give it a good purge to blow the air out

 

[hammers4spanner]

sounds airlocked to me connect cold to hot and give it a good purge to blow the air out

Was thinking that , that had a mixer put my hand over it tried blowing it through that way and ran it for few mins and left it but suddenly died off again after i had left

 

[quality]

it depends on the pipe run if it is an airlock, it can take quite a large volume of water too displace the air

 

[hammers4spanner]

I wouldn't think it's overly long run bit weird why it's airlocked tho out the blue

 

[quality]

Yes that is an odd one

 

[heliotrope]

If there is a ball o fix isolator check there is not a lump of debris
behind it.

Very often it may be a piece of foam insulation from the cylinder.

Best to first turn off cold feed before taking isolator off.

 

[hammers4spanner]

The weird thing is they said it slowed up over about three weeks until it nigh on stopped hence why they thought it was the tap.

 

[spanner]

Must be on a different hot run if the basement hot tap is working okay??

 

[jtsplumbing]

bet he's trying to talk them into a full house re -pipe, bit skint after Christmas

 

[turnpin]

How often is hot tap in basement used....maybe ask them to not use it for a while to see if it has any effect I wonder if this is where the air-lock is being caused by syphoning the leg supplying the kitchen tap.....regards Turnpin:dizzy2:

 

[hammers4spanner]

Must be on a different hot run if the basement hot tap is working okay??

Yea basement tap works fine its on other side of the house

 

[townfanjon]

The fact this slowed up over 3 or so weeks maybe suggests something has slowly blocked up ... .?

 

[hammers4spanner]

Gotta be either an airlock which starting to think it may not be or an old iso valve somewhere hidden and it debris has gotten over it .

The odd thing tho when i put my hand over the mixer and open hot then the cold i could hear gurgling around the house . Then it ran for a few mins so i turned it off and later had a call that its down to a drip again !!!!

 

[PlumbBobBob]

I recon that when you ran it for a few minutes it was just letting out the water you had put in from the mains. maybe do It for longer next time until the gurgling stops

 

[hammers4spanner]

Ran hot tho

 

[jtsplumbing]

Its got to be something in pipe, maybe a check valve some where, is it possible to trace pipe back, or even run a new supply ?

 

[Phil]

Last time I had this it was solved by purging air out of an unused shower tucked away in a bedroom.
I said...are there any other hot outlets in the house I don't know about..
I was taken to an un used bedroom there was a shower in a little walk in cupboard. Air spluttered out and hey presto, problem bath tap started working normally.

 

[hammers4spanner]

they do have a shower in basement which may not be used much

 

[Phil]

Showers, hidden outside taps behind ivy etc.