Vokera 20-80 rs flowmatic - No Hot water

[fergie69]

No hot water, Heating working fine
(although i've noticed the pressure rising when operating)

Basically i've stripped the three way valve and cleaned it . but the needle/pin that operates the micro switch is not moving.

when the three way valve was off and i checked the pin from the heat exchanger it was solid when water running but could be pushed when water was off. (seems ok to me)

re fitted and pin for valve and switch worked slowly and intermittently.

Basically will replacing the 3 port valve (vokera 3207) solve the problem or could it be some other part like diaphram or heat exchanger.

I am thinking of changing the boiler as i need to reposition it within the kitchen and its well over 10 years old i think
Just didnt want to do it this weekend if possible to repair it with a part costing about £50

 

[Agile]

I dont know why you think the heat exchanger is involved!

The usual cause is the diaphragm but it sounds as if you have not bothered to look at that.

The manifold section is often well sludged up but most repairers would just deal with the diaphragm is still working.

They are very solid reliable boilers but they are over 10 years old now. Unless you plan to keep it for years there no point in reconditioning it now.

Tony

 

[fergie69]

Not so much the heat exchanger as the diaphram in front of it.
(wrong terminology but in the rough location)
But this seems to be ok as it is solid when hot water is running and can be pushed in when not.

Was looking at replacing the 3 port valve as the repair but if it then requires other parts then it becomes expensive.
Hence buy a new boiler (looking at Ravenheat Condensing Combi Boiler CSI85BT Sedbuk Band B) and fit it in the new location and nurse old unit through till the weekend.

Other threads have mentioned my model of Vokera being good and worth keeping but things are starting to degrade such as switch covers, wiring.
My fear is a continual replacement till everything is new and ends up where the cost is double the price of the new unit.

 

[nickso]

replace the dhw diapragm and get a service kit for the diverter. that should cure all ills regarding the hw operation. the only issue you may have is getting the brass ring out that holds the diverter innards in, you may already have this out if you completely stripped it down.

you will also probably need the tiny o-ring that seals the front of the diaphragm section, iirc it doesnt come in any of the kits.