Vokera Linea 7 - little hot water

[Phil and Huyen]

I have a Vokera Linea 7 and the hot water gets luke warm and the boiler then cycles off again, where the water gets cold. This cycle repeates itself and makes washing dishes or having a bath nigh on impoosible. As for having a shower, it's almost impossible unless you like leaping in and out!

The central heating works fine and water pressure is upto 1.5 bar. Any suggestions would be greatfully appreciated.

Thanks in advance - Phil and Huyen.

 

[HarrogateGas]

Sounds like a blocked DHW heat exchanger to me.

 

[Strachan]

And me. Good little boiler, remove and clean it or pop a new one in.

 

[Agile]

Its the common problem of a blocked secondary heat exchanger because the installer could not bother or was not paid to power flush the system when the boiler was installed.

Tony

 

[Paul Barker]

It never ceases to amaise me how much mud my mgnetic filters catch before during and after a powerflush. The system goes on to create magnetight all the time.

I WOULD NEVER HAVE A COMBI AT HOME WITHOUT A MAGNETIC FILTER ON THE RETURN PIPE. I would clean it out regularly aswell.

The plastic piped systems are the worst for this in an order of 3 times more sludge follows a good cleanse, they carry on producing it. The systems fitted in plastic on newish estates round here are an absolute nightmare to have to work on.

They were easy to fit that's the only good thing about them. They were badly and unprofessionally designed and implemented with little thought of the future both in maintainability and in system condition. Most are piped from the loft without air vents a drop to every rad without drainoffs.

That's the building industry of today for you, no thought for what happens the week after they've gone.

 

[Phil and Huyen]

Hello one and all!

Thanks for all the suggestions regarding the heat exchanger - spot on! It has cured the fault! Hot water at last!!I also read with interest about the magnetic filter - this seems like a good idea. If anyone can recommend a particular brand, then it would be good, as I noticed that the heat exchanger was full of crud. I didn't bother cleaning the old one out as i've heard mixed results as to how effective this remedy is.

I just need to cure the loss of water now! I have to re-pressurise the system every 3 days, as it will drop from 1.5 bar to zero. There doesn't seem to be a physical water leak, as i have checked all visible pipes and joints and that amount of water would be very much in evidence.
Someone suggested Fernox leak sealer but i know the previous owner did this and it was that stuff which clogged up the heat exchanger to start with!

So keep those suggestions rolling! And thanks once again!

Best regards, Phil and Huyen.