fixmyplumbing

Simple explanations for plumbing problems

Combi boiler heat exchanger leaking

If the filling loop has been removed and capped so you are sure the combi boiler is not filling from the mains the heat exchanger is the only remaining cause. Combi boilers have a heat exchanger that takes the heat from the boiler and transfers it to the cold water coming from the water mains.  Modern heat exchangers are made from very thin stainless steel in the form of flat plates.If the steel fails either through corrosion or manufacturing faults the mains water can mix with central heating water.  The hole that is caused by the corrosion/fault is normally very small so the pressure rise is generally over several hours or even days.

The heat exchangers can’t be repaired so have to be replaced. This isn’t a DIY job so should only be done by a registered boiler engineer.

« Fixing the problem


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.

%d bloggers like this: