no hot water

[pho]

HI all,
went to get in the shower this morning and no hot water !, if I turn the centrl heating off and just have the water heating on you hear the pump start and then turn itself off straight away, i am not sure where to start. The boiler is an Ideal Classic lxff there are 2 honeywell 2 port motorised valves which appear to respond to the thermostat moving (how do you tell if they really open and close ?) . If I put the heating on the house gets warm and the hot water starts to warm up but when the hot water is on by itself the boiler will not fire, any hints where to start looking ? my best guess is that something electrical is not sending a signal back to fire the boiler but any help would be appreciated

thanks
Pho

 

[ollski]

i would say the motorized valve on the hot water side needs a new sychron motor, but can't explain why the pump / boiler are firing up...that would suggest the microswitches in the valve are making but power is being cut by a satisfied cylinder stat. the cylinder stat hasn't been turned right down somehow has it?

 

[pho]

thanks for the reply, no I took the cover off of the valve and then turned the thermostat down and watch the valve shut, then I turned it back up to 70 and the valve started to open and as it opened fully the pump kicked it for about half a second and then it all stopped again ! is there a switch in the motorised vallve that i can short to see if I can make the cicuit ?

thanks
Pho

 

[ollski]

try moving the lever fully across by hand but if your stat is making and breaking the circuit the fault will most likely be the synchron motor in the valve head.

 

[pho]

what does the lever do ? because if I move it the motor just pushes it back and the main shaft into the pipes doesn't seem to move (but it does when the motor moves it)

 

[pho]

another thought, do the motor heads microswitches in them ? do you know of any diagramatic representation of what they look like ?

thanks again

Pho

 

[breezer]

pho, to avoid confusion, if you want to add / edit your own post you can press the

button

 

[pho]

ok thanks

 

[ChrisR]

The lever opens the valve, (and you can hook it in that MAN position,) but not far enough to operate the microswitch which brings the pump and boiler on.

If the motor always starts to move but then stops it sounds a bit like the mechanics of the valve's head are stopping it - new head needed?

With the valve open (hooked on man) your HW will heat up whenever the rads are getting hot, until you get it fixed.

 

[pho]

excellent thanks, a couple more questions - are the replacement heads specific to the valve or can you get a generic head ? and is it hard to fit ?

thanks
Pho

 

[ollski]

depends...does your honeywell valve have a little dimple on the top?....if it does you can change the head for £60 (honeywell v4043) and half an hours work.

 

[pho]

it says F6-9847 on it....and no real sign of a dimple....had a look underneath and it is a 4043 so with any luck a quick swop, anyone had any experience of the replacement head from screwfix ?