Air in hot water flow.

[TBolt]

Hi Folks, I moved home last year and changed kitchen and bathrooms myself and British Gas did the boiler change (standard condensing as I wanted to keep airing cupboard).

I have a problem of hot water flow stalling and spluttering from the mixer tap in the kitchen (air in system?). No problem in bathroom or ensuite.

I have very low pressure in the hot system because I live in a bungalow. The cold pressure is very strong and I have connected both to back flush and this only solves the problem for a short period of time.

I have checked the cold water storage tank in the loft and the valve is working fine so I do not think this causes any airlock. However, the overflow is in action on a regular basis.

I have reduced the temperature on the thermostat (on hot water cylinder) but this has made no difference.

My problem may be related to the mixer tap at the sink (Leisure AQUADISC 2) this is the quater turn type and may not be working well with the low hot water pressure.

Will changing the tap help cure the problems?
Any reccomendation on what would be a good quality replacement?

Any advice is most welcome.

Thanks TBolt

 

[frank uk]

I get these now and again,no hot water out the bath tap,its ok everywere else,and they look at a fault with the pressure or boiler(combi),and when you ask"is the tap ok" "oh yet,didnt think"so i say tap faulty

 

[TBolt]

Hi Frank, thanks for prompt response.

TBolt

 

[JohnD]

I have checked the cold water storage tank in the loft and the valve is working fine so I do not think this causes any airlock. However, the overflow is in action on a regular basis.

you are saying that the cold water storage tank is regulaly overflowing but the ball valve is working correctly? perhaps it overflows during the night or when you are out and have not been running taps and fliush9ing toilets?

then you have high-pressure cold water leaking past a mixer tap and getting into the hot pipes, feeding back into the tank.

have you got a shower mixer?

have you got service valves on all your mixer taps?

 

[TBolt]

Hi JohnD,

I have lowered the ball valve in the cold storage tank and will check tomorrow if the overflow problem persists.

I thought that the hot cylinder was over expanding but will need to keep checks on this.

The water flow only stalls when the hot water from the tank reaches the tap. This takes a while because of the low pressure.

I do have a shower mixer and upgraded it for a new unit (both Mira).

I do have service valves to the mixer taps.

TBolt

 

[JohnD]

turn off the service valves to the mixers and see if that stops the overflow. If it does, that confirms the tap that has internal leakage. It ought to be the shower not the sink as UK sink taps don't (?didn't?) allow internal mixing. Don't know if this is true of the ceramic disk taps though.

 

[TBolt]

Thanks JohnD

The overflow problem has stopped for now.

I will try your tips if it restarts.

TBolt