condensing combi boiler drainage.

Firstly, I am being lazy in asking this question, as I am sure that the manufacturers literature will tell me the answer (somewhere!!!!!)

After quite a few questions in here, and lots of prodding and poking, I am now of the opinion that my daughters house would benefit from a new combi boiler. This would be to replace two boilers sited in the cellar ( the 2 boilers are not required to give sufficient heat, they are there because the house was converted from 2 houses)

As I understand the situation, it is now necessary to fit a CONDENSING combi, but I don't hear many good reports about them

Does this type of boiler need to discharge "condensate" (if thats the right expression) into a drain.? bearing in mind that this would be located in a cellar, and there is no surface water or foul water drainage in the cellar.
Also... best method to clean out existing system, without powerflushing

You'll probably have to pump the condensate.

Combis are fine, just look after them properly. Carefully consider your hot water usage and mains supply before selecting one


Drain the system and put a cleaner in for 3 weeks. Then drain and refill with inhibitor. Magnacleans are quite usefull too (threads on here about them).

Condensing boilers are as good or bad as non-condensing, depends on the model, quality of installer’s work and maintenance.
Contrary to common belief, they are not something new, been around since before the war.