Oil boiler / heating working fine. Water only tepid

[mdfman]

I have an oil boiler that seems to be working fine in terms of heating the house but less well in terms of the water which in the last few days is only lukewarm

I have an immersion heater which seems to work ok so I'm guessing its not a thermostat issue on the HW cylinder. I am wondering whether it might be the timer ~ the light for HW is on but it doesn't appear to fire the boiler.

Any suggestions would be welcomed

Thanks

 

[Boilerman2]

Just cos the light is on the programmer doesn't mean that a feed is going to the HW controls that said there are many possible causes - and no amount of guess work will diagnose!! is yours a fully pumped system or gravity HW - if it is Gravity hot water check the small header tank you might find the ball valve stuck and no water in the top of the system restore the water and your HW will restore HOWEVER if yours is the more common fully pumped type the fault could be the Cylinder stat or the Motorised valve or just an airlock in the cylinder coil depending on the layout.

some pictures of the airing cupboard layout would help, but as you don't sound to be very technically minded I would advise you to get a Heating Engineer to come and have a look!

 

[mdfman]

Thanks Boilerman 2. I have traced the fault I think to the actuator on the Hot water feed (there is a separate one for the CH)

When the Programmer is on for HW and the manual override switch is used the boiler fires. However the switch appears to be spring loaded so it won't stay in position.

I understand this can be replaced without having to drain any part of the system. Any further advice much appreciated

 

[Armo74]

Make and model of valve will determine whether a draindown is needed.

It sounds like it is probably just the motor that has gone these can be purchased seperatly but make and model is needed anyway.

 

[mdfman]

Thanks - its a Myson MSV 222. The operating light is on but nothing happening unless in manual override

 

[oilhead]

It is possible to change the synchron motor, but very fiddly on this actuator. Complete actuator will solve the problem.

 

[mdfman]

I'm happy to change the whole actuator if that's easier - think I can get similar one for about £45.

Question is though can I do this without draining the system?

Thanks for your help

 

[oilhead]

Yes, undo 2 screws in corners of actuator

 

[mdfman]

Thanks - one other question - mostly when I push the Manual override lever to get some HW there is resistance - but yesterday morning there was none, suggesting the valve had opened ~ today its back to previous form.

Probably need to change the actuator anyway but this would seem tosuggest its not completely Kaput?

Any views appreciated

 

[Boilerman2]

Change it!!