Another boiler pressure drop question.

vicky11

The pressure in my Worcester, combi boiler 28CDi drops to 0 every 4 days. The heating engineer said I may have a leak in the pipes! This terrifies me as we have tiles on all our wooden floors and they would have to be smashed out. He has isolated the heating system, so we only have hot water at the moment and is calling back in a few days to see if the pressure has dropped (it hasn't so far after 10 hours). If the pressure doesn't now drop does that mean there is a leak in the pipes? Also how can he tell when we still have hot water, so the boiler must still be working and coming through some pipes, it doesn't make any sense? Thanks 

nofoollikeold

1. If the pressure doesn't drop with the boiler isolated from the central heating circuit, then the leak is in the central heating circuit.
2. The hot water circuit is completely separate from the central heating one, so isolating the central heating won't affect hot water.

vicky11

Is there any other reason why this could be happening besides a leak? We are in our 70s and are self isolating, so having tiles smashed out and floorboards up, with lots of different people in the house is out of the question. We would rather live with no central heating for now, would this be possible/ or / keep putting the pressure back up every 4 days. Any advice would be helpful. Thank you

nofoollikeold

1. Wait until your plumber has been and determined whether the leak is in the boiler or the system.
2. There are ways of finding a leak other than opening up all the pipework.  However, it is relatively expensive, so you may be looking at an insurance claim.  The insurer would normally pay to find the leak, but not for the work to repair it or any consequential costs.  
3. Any leak could be on a connection / connections to radiators.  Once the heating is on, try tying a "bow" of toilet paper or kitchen roll to each pipe as it comes out of the floor into the radiator, just below the radiator valve.  If the paper bow sags, you are likely to have a leak on that joint.  They can be easily fixed without ripping up floors.  
4. If the leak persists, determine how long it takes the boiler pressure to fall from 1.5 bar to 0.8 bar.  If this is a week or so, then you could, as a temporary measure, just keep topping up the pressure.  However:
4a. Leaks rarely cure themselves, and usually get worse.
4b. Every time you top up the pressure you let fresh water into the system, which is otherwise sealed.  This air contains oxygen, which will in time cause corrosion of the insides of your radiators.  Systems normally have an inhibitor chemical added to prevent this, but constant topping up dilutes this chemical.
5. I wouldn't worry too much:
5a. There may not be any leak on your system.
5b. It's quite likely any leak that is present will be at one or more accessible connections.  
5c. There may be alternative solutions to a pipework leak, such as re-running pipes at skirting board level.  Not aesthetically pleasing, but might be a good trade off against disruption.

vicky11

Thank you so much for taking the trouble to reply, and your very reassuring advice,