Glow Worm Combi hot water problem

[coatsy35]

Hi,


I have a Glow Worm 38 cxi boiler which seams to have developed a problem with the hot water supply.

It doesn't kick out 15litres per minute which it should do, (I have tested the cold water supply just before the inlet with nothing else turned on and I'm getting nearly 20 litres per minute) the boiler only outputs 10 litres per minute maximum in summer or winter.

Also the temperature of the water fluctuates steadily, i.e. when running a tap it will be as hot as it should be then it will get cooler and then over a minute or so go back towards the correct temperature (really annoying when having a shower!!!!)


I have no error codes flashing up and all sounds as it should. Is there anything I can check before I have to call a plumber out?


Regards

Dan

 

[mickyg]

Sounds like a scaled plate heat exchanger. Are you in a hard water area?

 

[coatsy35]

we are in a hard water area, but the boiler runs off a water softener (salt filled) and has been since day one, the boiler is never run on hard water, do you think this could still be the problem?

 

[mickyg]

well thats what I would say from the fault description. throws a spanner in the works with the softener, but probably still first thing to check.

 

[coatsy35]

If it is scaled is it a take out and clean job (what with? ) or a new one?

 

[mickyg]

either or. Sometimes can be descaled, but not easy.

 

[bengasman]

Did you use to have a higher flow of dhw with this boiler?

 

[coatsy35]

yes we did have a higher flow, and a more constant temperature.


Do you think the temperature fluctuations are linked to the scaled heat exchanger?