Losing Pressure on a Daily Basis
The physics is very simple - there is a leak somewhere in the system! The leak can only be at one of these three points: 1. the boiler pressure relief valve (PRV), or 2. the boiler main heat exchanger, or 3. on external pipes and valves. But, to find out the actual point where a leak is occuring is sometimes not straightforward and solved in just one visit. So, we wrote this Diagnosis Strategy to help our customers understand the problem.
As a Herts Boilers standard policy, we offer "no fix no fee" on most of our repairs. But unfortunately with a pressure problem on a sealed system we charge by the number of visits, not by the outcome, although we will do our best to find the leak and get it fixed. The reasons for this exception are: 1. if it is the boiler's main heat exchanger that is leaking, some customers will go for a new boiler, or we don't always get main heat exchanger replacement jobs. 2. We are not experts at external pipe leak fault finding (external pipes mean the pipes outside the boiler which are all over your house).
Once your boiler is losing pressure on a regular basis, it is also advised to check around your house, eg, is there any radiator valve leaking, is there any wall corner that is damping, or is there any wet floor board?
Herts Boilers also maintain this blog site: http://www.boilerblog.co.uk/