Unvented cylinder pressure - but boiler now loosing pressure

[marked]

Hi.

My unvented cylinder was recently replaced with a Santon Premier Plus Cylinder. This was done by a plumber qualified for the job. He also fitted a magafilter and flushed the system clear + filled inhibiter.

The problem is that the boiler (Voykera Mynite 28e) is now loosing pressure over the course of the week and needs to be filled weekly.

The plumber has checked all radiators etc. and cannot find any leak or cause. This plumber is quite new at the job and has only had a few months of working experience after qualifying - is he missing something?? How can the change of cylinder cause this problem? The boiler didn't loose pressure for years and now after the fitting it suddenly is - there must be a connection!!??

Could the boiler have been affected or strained due to the flushing (it was making a noise when running after the flush)?

What is the likely cause - any help greatly appreciated.

 

[lightning]

Check prv pipe for water discharge from boiler.as expansion vessel may need recharging in boiler

 

[dcawkwell]

Possibly if he didn't bleed the air from the top of the boiler when
he stated it up the heat exchanger was damaged when the boiler fired.

Also possibly that if all that was holding the heat exchanger together might
have been washed away with the flushing and is now leaking.

Been to a customer who replaced a radiator then fired the boiler
up without bleeding the air out of it. Whoops new heat exchanger £400.

The mynute has a bleed nipple on the top of the boiler.