main combi 30HE boiler help please

[wiibeechroad]

Hi, Im having a problem with DHW, runs hot and cold,

Changed the diverter valve, still having the problem, advice appreciated,
Thanks in advance.

 

[terryplumb]

If when running a hot tap ,the temperature gets hot ,goes cold ,then hot again,then cold ,repeatedly you probably have a blocked plate heat exchanger.

 

[wiibeechroad]

thankyou for helping with this problem,,is this much of a job to unblock?

 

[terryplumb]

Probably best left to an engineer to be frank. It has to be removed from the boiler ,and you would have to use powerful acid to clean it. Sonic cleaning equipment would be used by British Gas for instance ,and its quite expensive !!

 

[wiibeechroad]

ok will have a look into this, thanks again for the advice