Gas boiler - Heat but no hot water

_Kaiser_

Hey all,

Yesterday I went for my morning shower as normal only to discover the water was only lukewarm. Same thing again this morning but the heating is working fine??

Haven't adjusted anything before this, pressure is OK but have tried all the taps and all the same

Boiler is a Sime model with an on/off and temp control but that''s all. Have checked the pipes beside the tank and only one of them is hot.

Any ideas?

(Pics attached - ignore the mess!)

RJF

The flow of hot water through the coil is regulated by the white thermostatic valve with the small silver wire going to the sidewall of the cylinder where the insulation is cut away. It is possible that the valve is sticking. Remove the valve head by turning the ridged nut below the plastic head anticlockwise while holding the head steady. It should be only hand tight but if you need to use a pliers do so carefully. There should be a pin exposed now. This pin may be sticking. If you have WD40 spray a little on it. Give it a few minutes and PRESS down on it using the side of the pliers or other solid object. Do not hit it. If it is already stuck all the way down or moves down and does not come up then use a pliers to pull it up. Do not use excessive force. Using the pliers to move it up an down in small increments should do the trick. When it is moving freely you will be able to push it down and it will return up of its own accord. Replace the head with it turned fully open and hand tighten only. Hope this helps.

_Kaiser_

RJF wrote: »

The flow of hot water through the coil is regulated by the white thermostatic valve with the small silver wire going to the sidewall of the cylinder where the insulation is cut away. It is possible that the valve is sticking. Remove the valve head by turning the ridged nut below the plastic head anticlockwise while holding the head steady. It should be only hand tight but if you need to use a pliers do so carefully. There should be a pin exposed now. This pin may be sticking. If you have WD40 spray a little on it. Give it a few minutes and PRESS down on it using the side of the pliers or other solid object. Do not hit it. If it is already stuck all the way down or moves down and does not come up then use a pliers to pull it up. Do not use excessive force. Using the pliers to move it up an down in small increments should do the trick. When it is moving freely you will be able to push it down and it will return up of its own accord. Replace the head with it turned fully open and hand tighten only. Hope this helps.

Thanks for this... I'm not 100% I follow though (sorry, IT is my game not plumbing ) - is it this bit you mean? (circled in blue)

RJF

Yes, what is that rope doing there? Needs to be removed.

RJF

First step remove the head-white plastic part as described and let me know can you see the pin. That rope might be supporting the red expansion vessel but it should not really be tied to the pipework. Some galvanized banding fixed to the wall would be better-not a great installation.

_Kaiser_

RJF wrote: »

First step remove the head-white plastic part as described and let me know can you see the pin. That rope might be supporting the red expansion vessel but it should not really be tied to the pipework. Some galvanized banding fixed to the wall would be better-not a great installation.

No the rope just seems to be part of a small shopping bag they got jammed in there so got it out of the way easy enough.

Not having as much joy with the nut though.. It does move about half a turn counter clockwise but that's it and I don't have a suitable pliers to hand tonight.

Will have to have a go in the morning (better light too) and see if I can get it loose but will update you either way then.

Really do appreciate your help though!

RJF

Put a downward pressure on the valve head with one hand to keep it sitting square on its seating and turn the nut backwards and forwards with the other. They can be a bit sticky but should loosen. Good luck.