Cold water ok but no hot water?

daveg

Since yesterday the hot water has stopped all over the house. However the cold water pressure is fine. Have checked the 2 on/off levers on the tank and both are set to on. Any idea's what it could be?

ircoha

Winging it here as we dont have a great amt of detail.

Assuming ur system is a standard open system with a standard immersion cylinder etc if the HW has stopped flowing then it is prolly that the cold water feed to the cylinder is blocked, could be a bit of rockwool fell into tank and got sucked in.

Like wise the outflow from the top of the cylinder could be blocked for the same or similar reason.

While the following is unlightly, I have seen some houses where all the cold feeds are from the rising main, which in ur case would mean that the tank in the attic is not filling anymore, ball cock could be stuck.

tapest

daveg wrote:

Since yesterday the hot water has stopped all over the house. However the cold water pressure is fine. Have checked the 2 on/off levers on the tank and both are set to on. Any idea's what it could be?

Hi daveg
It might be quite simple and quite simply cured... posdsible airlock ?? especially if system was worked on or water off for long period. If you have normal plumbing system, use mains pressure to blow back through hot system. At kitchen sink
a) if you have pillar taps join them together with short garden hose and two tap fittings.....or
b) if you have mixer tap remove anti-splash device (small piece of plastic) from end of outlet. Cut a thin peastic bag and insert the a-s plastic into bag and screw it back on.
Now no water can escape into sink. Open Hot tap fully first followed by cold tap. Main water now pushes back up through hot pipes to cold header tank. If your overflow is as it should be then when tank is full (overfull in fact) you'll see water coming out of overflow.
Does not always work but for me success rate is better than 95%
That's if it is an air lock.. As regards a possible obstruction it may move( but won't remove it). Worth a shot and may narrow down fault
Regards
t

GreeBo

just to confirm, are you getting water out of the hot taps but its cold or are you not getting anything out of them?
Did it stop suddenly or did one of the taps just peter out one day?
As above, check the tanks in the attic, if you have access, tap the cylinder, is it hollow or full sounding?

daveg

tapest wrote:

Hi daveg
It might be quite simple and quite simply cured... posdsible airlock ?? especially if system was worked on or water off for long period. If you have normal plumbing system, use mains pressure to blow back through hot system. At kitchen sink
a) if you have pillar taps join them together with short garden hose and two tap fittings.....or
b) if you have mixer tap remove anti-splash device (small piece of plastic) from end of outlet. Cut a thin peastic bag and insert the a-s plastic into bag and screw it back on.
Now no water can escape into sink. Open Hot tap fully first followed by cold tap. Main water now pushes back up through hot pipes to cold header tank. If your overflow is as it should be then when tank is full (overfull in fact) you'll see water coming out of overflow.
Does not always work but for me success rate is better than 95%
That's if it is an air lock.. As regards a possible obstruction it may move( but won't remove it). Worth a shot and may narrow down fault
Regards
t

Thanks a million. Forcing the cold water into the hot water feed cured it. Must have been an airlock.

Thanks lads. Boards saves the day again....

tapest

daveg wrote:

Thanks a million. Forcing the cold water into the hot water feed cured it. Must have been an airlock.

Thanks lads. Boards saves the day again....

No Prob Daveg...A handy little fix, but remember if you had not got the water off lately, there could possibly (although unlikely) be an obstruction, and all you did was moved it out of the way ....It may return.
t

daveg

tapest wrote:

No Prob Daveg...A handy little fix, but remember if you had not got the water off lately, there could possibly (although unlikely) be an obstruction, and all you did was moved it out of the way ....It may return.
t

Thanks T. I'll check the tank for obstructions if it happens again.

Thanks again