Vaillant Boiler No Hot Water

[alrg500]

Hi, wondered if anyone could help me as I have a fault with my Vaillant Turbomax boiler.

When you turn the hot taps on the boiler fails to light and supply hot water.

But if you turn the heating thermostat up so the boiler is lit and then run the hot taps then you get hot water although the tap light is still off.
Just wondering if there was a simple reason for this that I could have a look at fixing myself?

Thanks Allan

 

[peter the plumber]

common fault with these.The diverter valve is faulty.This can be done by yourself as no gas work .Isolate boiler drain down boiler remove pump,undo nuts to plate to plate a few nuts on diverter.Make sure you use new o rings and washers with some silicone grease.

 

[Gasguru]

Could be the diverter microswitch, the bow (the little white lever that transfers diverter motion to the switch) or the diaphragm or something else entirely

Check if the small microswitch on the diverter (RHS) is activated when a hot tap is opened. If it is check the contacts with a multimeter..they can fail.

Check the bow moves up/down...sometimes they snap...complete diverter replacement best option.

Otherwise maybe a perishished diaphragm...service kit available but it's not an easy diy job and you don't get all the seals anymore. or replace entire diverter.

 

[namsag]

Diaphragm kit is a fiver, divertor a ton. Diaphragm does not always cure it though and it ay need the whole valve