calydra comfort no heating but hot water fine

[smokey67]

hi

Been having a few prob with a calydra comfort 100, in the last week i have had to replace the fan and the pcb and now the heating isnt working but the dhw is fine. There are no fault lights flashing but i suspect its the three way valve but was wondering if there is a way to test it.

cheers

 

[mountainman]

Your probably right that its the diverter valve, unless someone has inadvertently turned off the flow or return valves.

I suppose with the benefit of hindsight it would have been a better idea to renewed the boiler.

 

[smokey67]

yeah if i had of known at the start it was going to give so much bother i would of advised to change it but just have to hope nothing else goes wrong

 

[Gary71]

When you say the hot water is working, is it the plate heat exchanger or the stored water you're feeling when you first open the tap, if it's the plate heat exchanger the water gets hotter as you restrict the flow.

As this boiler is hot water priority you will get no heating till the stored water is up to temperture.

Also those PCB's have to be set up for the boiler and don't normally work out of the box.

 

[smokey67]

i was back at the boiler later 2day and there was still no heat, the stored water should of been up to temp by then. didnt know the pcb needed set up i thought it just needed connected, would that effect the dirverter valve not opening for heating

 

[Gary71]

Hot water priority, no heating till the stored hot water is satisfied, takes about 14 minutes for the stored water to achieve temperture, it's common to have thermister issues or a lack of movement around the coil both effecting heating, if it was the diverter valve I would expect a fault code of some description but there's always a first.

PCB's have jumpers on them that change the characteristics of the board depending on the position, that board needs to be told its in a boiler with stored water (from what I remember) ring Ariston tec for jumper positions if your Gassafe and if your not then step a way from the boiler.

(I see you already have a new diverter fitted which would make it less likly to be the diverter)

 

[smokey67]

that was a different boiler that i changed the diverter valve, it was stuck in the heating position and as the boiler is hot water priority it would not fire. there is no fault codes in manual for valve stuck in dhw mode, only stuck in heating and since this one seems to be stuck in dhw mode i presume the boiler would fire up without detecting the fault. will give the tech guys a ring about the pcb.

cheers

 

[smokey67]

i am gas safe but dont do alot of work on boilers, where i live 95% of the boilers are oil fired

 

[Gary71]

The PCB is the same one for a britony combi, when you get the board it comes with a bit of paperwork which tell you what the jumpers do, I think there is a jumper for stored water.


If you have confirmed that the stored water is up to temp and the PCB is right then the diverter valve would be looked at next, I used to carry one and plug it in before changing it to see if it fired.


Although there's no fault code for diverter valve stuck in hot water position sometimes the boiler would fire with a defective diverter valve leading it to lock out on over heat.




Without telling you how to suck eggs, I always remove my heating wires and fit a link to confirm continuity.