worcester 24cdi combi...... no hot water.

[candlekungfu]

hi guys, wondered if someone can help at this cold time of year. i have a worcester 24cdi combi which i have replaced the diverter valve on earlier this year. what's now happening is when i turn the hot water on the boiler ignites and the water starts to get hot then after 10 sec's it turn's off and then after another 10 sec's it ignites again. i tested the micro switch on the diverter valve and it's not that, any ideas?

 

[wnjswozo]

high limit stat

 

[diesel_ltd]

hw temp sensor i would say, does it work ok on heating?

 

[candlekungfu]

heating is fine its only the hot water which go's on and off.

 

[candlekungfu]

well i changed the domestic hot water sensor but no change. any ideas anyone?

 

[candlekungfu]

any one? also where is the high limt stat on a 24cdi?

 

[bm1289]

Have you checked divertor valve pin is making micro switch?

 

[washer]

Sounds like a blocked plate heat exchanger

 

[candlekungfu]

thanks washer, ill take it off tomorrow and let you know how i get on.

 

[peteisfishing]

had a similar problem recently on a 42 cdi, turned out to be the flow sensor, signal was made then became irratic, fixed by fitting a new one. thats if it has a flow sensor.....not to familier with WB

 

[candlekungfu]

where abouts is the flow sensor, ive checked the micro switch on the diverter valve and its not that, checked the heat exchanger and its not that, checked the heat thermistor's and its not them, doesnt seem to be the air flow sensor either so apart from the board im running out of options!

 

[peteisfishing]

It has a DHW sensor behind the plate to plate HE

 

[candlekungfu]

ive changed the dhw sensor behind the water to water heat exchanger. so its not that.

 

[candlekungfu]

Over


ive checked the micro switch on the diverter valve and its not that, checked the heat exchanger and its not that, checked the heat thermistor's and its not them, doesnt seem to be the air flow sensor either. ive changed the mother board now and its not that! what else is there? what should be the ohms on a Overheat thermostat? on the manual it says:

temperature
shut-down if
water
temperature
8°C above set
value

 

[mikegas]

its a switch so just test for continuity you can link it out just to check

 

[candlekungfu]

hi mikegas, so if i bridge the wires to the overheat thermostat, that will tell me if its that or not? also when i run the hot water it now comes out luke warm.

 

[washer]

You are obviously not gas safe registered, if I were you just call in a professional. He would of had your boiler up and running ages ago.

Bridging out gas safety devices, for fault finding purposes, shouldnt be done by someone who doesnt understand how they work.

 

[candlekungfu]

You are obviously not gas safe registered, if I were you just call in a professional. He would of had your boiler up and running ages ago.

Bridging out gas safety devices, for fault finding purposes, shouldnt be done by someone who doesnt understand how they work.

well washer before i spend a couple of hundred on a plumber for a £20 part i thought i would try to find the fault myself considering i changed the diverter valve with ease i thought something stupid i could also do with ease which is why i was on this forum asking for help on identifing the problem otherwise whats the point of it, i may as well just call a plumber!
i was going on mikegas's opionion that the overheat thermostat is a switch and that it can be linked out which is why i asked (does that mean bridged)!

 

[hihowudoin]

Over


checked the heat exchanger and its not that

you say you "checked" it have you flush it through with chemicals as the waterways are very narrow and just because water can flow through it off the boiler doesn't mean flow is sufficient in situ.

 

[candlekungfu]

you say you "checked" it have you flush it through with chemicals as the waterways are very narrow and just because water can flow through it off the boiler doesn't mean flow is sufficient in situ.

yes i flushed it and put some lime scale acid remover and its clean as a whistle.

 

[spooney54]

Hi Candlekungfu,
Just read your post on no hot water on your boiler.
I have a very similar problem on my 24cdi rs and wondered if you eventually found the cause of your hot water problem.
Tried most of the things that you have but no success as yet.
:banghead:

 

[mfgs]

Try calling a Gas Safe registered engineer. That will get it working.

 

[spooney54]

Hi mfgs,
I am gas reg.just trying to get some info on a fault. Just getting into boiler repairs. Done a few courses on the condensate boilers,Worscester, Ideal, Glow worm, Remah, Vaillant. Much different when your out in the field on your own though.
that is why im asking for sensible advice on this forum.
Any suggestions yourself mate other than above.