Domestic hot water problem

[terryplumb]

Your pics are not sharp enough in focus ,but I suspect the leak is from higher up ,and tracking downward, collecting on the nut .
You should be able to see staining on the vertical pipe above the nut where water has dribbled downward.
The top of the pipe has an air release valve on it ,and they are well known for slightly weeping.

 

[Vicario]

Cheers, everyone. I have a servicing and repair contract with the company that fitted the system so I'll give them a ring.

 

[Vicario]

Terry - you're spot on with the leaking air nut. I got my torch and it was then very obvious. Is that the cause of the dodgy valve, do you think?

 

[terryplumb]

Terry - you're spot on with the leaking air nut. I got my torch and it was then very obvious. Is that the cause of the dodgy valve, do you think?

I doubt it,unless water has gotten inside the valve, which is unlikely . It would more likely continue to run downwards ,away from the metal cover.

 

[Vicario]

The engineer came and tightened the air vent nut, which stopped the leak. He then tested the valve and confirmed that it was letting through the boiler water and that it needs to be replaced. He said that this involved draining down (top floor) so I was wondering if, as the warmer weather is approaching, could I wait a bit until the summer/autumn to have the work done? I've turned down the boiler flow temperature and, after several experiments, I've got the DHW at a safe temperature whilst still having hottish radiators. My question is really if it's OK to have the dodgy valve for a few months or is that likely to cause more problems? I suppose it's not very economical, but we have an electric shower so we don't use a lot of hot water from the taps really. I'm not being penny-pinching - we have some plans for reorganising the upstairs rooms and might want a new radiator sometime this year in an unheated box room, so if they're going to drain down anyway, that would be a good time to get everything done. All advice welcome.

 

[terryplumb]

The valve is faulty ,could it get any more faulty ??
Yes it could, and fail to start the boiler.
Should you do anything now ?
Entirely up to you.

 

[Vicario]

Thanks, Terry. How would a faulty valve stop the boiler - just interested to know really? From April I could turn it off completely and just use the immersion heater so I suppose that's an alternative. This could all have happened in November, so I suppose I can't complain too much.

 

[ericmark]

OK, I am an electrician, not a plumber, is the thermostat in a hole in the insulation? it seems to be just on top?

 

[terryplumb]

The valve is faulty ,could it get any more faulty ??
Yes it could, and fail to start the boiler.
Should you do anything now ?
Entirely up to you.

The motorised valve sends voltage to the boiler to fire it up. If the valve fails and it's internal micro switch is open circuit the boiler will not fire up for central heating.

 

[ChrisJP]

OK, I am an electrician, not a plumber, is the thermostat in a hole in the insulation? it seems to be just on top?

If the thermostat is not in not contact with the wall of the cylinder, it will be calling for heat even when the water in the cylinder is at the desired temperature, because the thermostat will not "see" that temperature.

 

[Vicario]

The insulation has been removed and the thermostat is in direct contact with the metal side of the cylinder.

 

[Vicario]

The engineer is coming next week to replace the motorised valve. Can you advise what exactly he'll need to drain down so I can be ready. I'm particularly keen to know if he'll need to access the little F&E tank in the loft - a bit of clearing up this weekend if he does! (It is a 'he' by the way, as it's my usual bloke). Will the hot tank have to be drained off too? Pictures are higher up in this thread.

 

[Madrab]

is the thermostat in a hole in the insulation

Yep -

 

[terryplumb]

It would be prudent to examine the condition / cleanliness of the loft tank before draining any of the system. If it is full of crud you don't want that to get into the system.
The hot water cylinder doesn't need to be drained of domestic hot water.