Please help - Vokera boiler barely working.

[mikeyw]

Pumps knackered.

Is there a test to confirm that gigz ? - its certainly one of the possibilities for sure but what is pumping the hot water around ?

 

[TCCHeating]

Pumps knackered.

but what is pumping the hot water around ?

Nothing. It has a bithermic heat exchanger

 

[gigz]

Take the centre screw out and put a terminal screwdriver in the hole, it should be spinning. Protect the boiler from a bit of water coming out of the hole.

 

[Samuelle22]

Hey Mikey,

If you have a pro coming out tomorrow, they should know much more than me. The thing that got me though was when you said that the flow pipe was very hot. That would be an indicator of a partial blockage afaik.

Also, as vulcan says, I know some modern boilers don't have diverter valves, but how the f does a boiler work without a heat exchanger?

Edit: As far as I know, modern heat exchanges are more likely to get clogged with little bits of oily flaky **** than older ones? Anyway, my old boiler seems good to go for another winter. It's running like a trooper after half an hour of back-flushing. All fingers crossed and very very hopefully, see you next year (and I know you pro power-flushers are just wishing me to fail

 

[TCCHeating]

Also, as vulcan says, I know some modern boilers don't have diverter valves, but how the f does a boiler work without a heat exchanger?

I think you mean how does a combi work without a divertor valve and secondary plate heat exchanger. The answer is with a bithermic heat exchanger. Vokera and Worcester amongst other manufacturers have used this design with limited success in the past.

Intergas currently use an updated version of this design philosophy on their combi boilers. And I am told that it works very well for them.

 

[gigz]

The thing that got me though was when you said that the flow pipe was very hot. That would be an indicator of a partial blockage afaik

Not necessarily, the pump shunts the water around the system. If its knackered the boiler will still heat the water up until it senses its either hot enough or its not moving, then it will shut the gas off. The flow pipe will get hot because heat rises. Pumps knackered.

 

[PullerGas]

Without standing in front of it & testing, my first check would be thermistor. Second check would be circulation pump & lastly system crud.

 

[mikeyw]

Thanks guys - some great advice here, will pass on to the heat engineer to help him with his diagnosis

 

[mikeyw]

Well he fixed it The boiler was ok but he cleared a few bits out of it.

These two pipes were coked up very badly, it would appear the last plumber who previously looked at the problem moved these around to see if they we blocked and loosed the deposit thus blocking the valve they flowed into!!!

The deposits were like charcoal and took a lot of cleaning. There's cleaning products in now so should loosen up the remaining crud but bl00dy hell the system is like toast now, every rad is red hot, something we've not experienced for years and years.

As you can imagine Mrs W is very happy !

Thanks for all the advice

 

[mikeyw]

Here's a few of the deposits for others reference

 

[Agile]

If it's the model I think it is you don't have a diverter valve or domestic plate heat exchanger. Good you're getting someone out.

And it does not run the pump during DHW delivery either!

Tony

 

[mikeyw]

DNW ? - hot water ?