Common Problem

[Stanios]

Hi guys, I am coming across this same problem time and time again on combis old and not so old.
In hot water mode boiler runs full rate then anywhere from 5 to 30 seconds later the flame goes out, any temperature on display goes mega high pump runs untill temp drop then relights 5 sec later and so on.

Some of these boilers will work fine on central heating others will do the same thing on central heating.

The diagnosis will often be blocked heat exchanger, presumably a dirty system is likely to have both heat exchangers in bad shape. So what is the best cost effective solution if the customer is reluctant to get a new boiler? Flush, replace plate to plate or insist on a new boiler?

 

[ShaunCorbs]

replace plate if not stupid high price and check system quality (heating)

 

[Masood]

Basically as Shaun said. I do try and clean plate heat exchangers before replacing, works around 90% of the time...

 

[Leo21]

Basically as Shaun said. I do try and clean plate heat exchangers before replacing, works around 90% of the time...

As above, but explain it could happen again, and why it may happen again. Stuff like this keeps us in work.

 

[Stanios]

Cheers guys, if it kettles and cycles on central heating mode would a powerflush help or just insist on new boiler?

 

[ShaunCorbs]

Cheers guys, if it kettles and cycles on central heating mode would a powerflush help or just insist on new boiler?

Depends will require a flush either way so nothing to loose with old boiler

 

[AWheating]

clean plate and make sure customer understands that you have treated the sympton not the cause then quote to flush and fit filter with possible new plate. Sometimes cleaning the plate works for a while, sometimes its blocked again in 2 weeks or less.