What causes pressure drop?

[Tinkerj94]

My boiler is a new build boiler, currently 8 years old.

The boiler has been working perfectly with no issues at all! We had our routine boiler check and ever since the boiler keeps losing pressure.

The boiler company insist the boiler is fine and that we MUST have a leave somewhere. They have told use we will need to smash the tiles off the wall in our kitchen and if there’s no leak the floor will need ripping up.

I have since spoken to another plumber who has kindly bled our radiators and had a look at our property to see if there is a noticeable leak and is there is an issue with our radiators.
He advised pipes are rarely in the floors for a new build property and if we did have a leak it would be visible in our walls.
We asked if a leak detection service would be needed and confirmed it would be a waste of money as any leak would appear in our ceilings or walls.

What else could cause a pressure drop? Is my boiler plumber missing something? They failed to acknowledge that un-bled radiators could cause a pressure drop. Has he missed something else?

 

[Deleted member 120897]

You wouldn’t necessarily see a leak in the walls, depending on how much insulation there is and how long the “leak” has been going for.

Have you or anyone else checked the pressure relief discharge pipe (a copper pipe that usually terminates externally)?

Depending on how cheap the trv is that’s been used, check there, had a few leak from the pin, but usually visible.

8 Years old, has it been serviced properly, and has the expansion vessel been charged?

 

[townfanjon]

What boiler is it please , and when you say boiler company do you mean the manufacturer

 

[ShaunCorbs]

Easy way to tell turn heating and hot water off eg turn boiler off over night and close the valves below the boiler eg the first and last valve 22mm pipes

Take a picture say 11pm check next morning let’s say 8am has it dropped if yes boiler if no system

Open the valves up does the pressure drop if yes system if no the boiler needs a couple of parts replacing that should of been done when servicing