vokera flowmatic 20 80

[michaelj76]

Im a gas engineer and would like some advice.i was called to a couple of flowmatics with problems.The first one is when you try the HW it will come on but then try it again and it wont it seems to come on when it feels like.The pins on both manifolds come out enough to press the microswitch.The Fan is working and the pump works and i encounter this on a few flowmatics its doing my head in.The other problem on another flowmatic is it is constantly losing pressure even after replacing the PRV and the expansion vessel ........... any ideas

 

[DP]

Put query on Combustion Chamber. You will have no probs accessing this section as a RGI

 

[superdupergasman]

If the fan is running and nothing else happening then sounds like you have dirt in the venturi tubes. remover combustion hood to remove venturi and clean ....losing pressure could be from leaking main heat exchanger look for stains on the white mats inside combustion box and sooting at either end of the HE.

 

[michaelj76]

Hi DP having scoured this site a few times to fine tune my fault finding skills i get the impresion you know a thing or two.But i am new to this site so tell me please what is combustion chamber

 

[michaelj76]

Hi superdupergasman.I was being drawn to the venturi problem after viewing this site i will try tomorrow as i have to go back with a PCB to try.The flowmatic thats losing pressure,there are no visible signs of any leaks any where thw propertys belong to Anchor Housing so i know they can afford to replace them with nice new greenstar 24i coz the flowmatic is a pile of ****e

 

[superdupergasman]

well the quick way to check the venturi's is to unscrew the case and let more air in then the boiler should fire and bob's your uncle.


you could put internal leak sealer into the system for the pressure drop if you are sure its from the boiler as if its a leak on hidden pipework then new boiler will still do the same.

 

[michaelj76]

no superdupergasman i have checked all rads and all pipework and the tennant has said she hasnt seen any wet patches its a ground floor flat with concrete floor so all pipework is exposed

 

[michaelj76]

superduper do you mean unscrew the combustion chamber or the area the venturi is located

 

[michaelj76]

superduper do you meen unscrew the combustion chamber or where the venturi is housed

 

[tonybhoy]

superduper do you meen unscrew the combustion chamber or where the venturi is housed

He means take off the combustion chamber cover and fire the boiler if it fires then the venturi is yer man if it doesn't then it'll be the fan/APS or pump.

The venturi on these is a pig to get to BTW.

 

[twgas]

think he meant front cover,
check the air break on the diverter, between diaphagm housing and diverter valve, they do tend to dry as they leak because of the heat so a thorough check is required

 

[scatmanjohn]

The other problem on another flowmatic is it is constantly losing pressure even after replacing the PRV and the expansion vessel ........... any ideas

Why did you replace these parts?

The flowmatic thats losing pressure,there are no visible signs of any leaks

Have you checked the heat exchanger yet?

thw propertys belong to Anchor Housing so i know they can afford to replace them with nice new greenstar 24i coz the flowmatic is a pile of s***te

 

[michaelj76]

yes i checked heat exchanger there are no leaks anywhere

 

[twgas]

did you check the div/water section air break, could wrap tissue round it and check it later for stains.