Pipe Advice Magnaclean Professional 2

[Rallyingace]

Hi,
i tried to change the rotation of the picture but couldn't,
the pipe to the left is the return from the radiators into the boiler,
I'm unsure as to what the pipe coming off of it is, I'd like to think it's a pressure release valve/pipe,
I'm fitting a Magnaclean professional & freezing the pipe below what I think is the pressure release valve,
I'll be closing the valve going into the radiator then freezing the pipe,
then removing the section of pipe,I'm just concerned as to how much water will come out thru the pressure release valve,
Any help would be greatly appreciated.

 

[KingDoey]

Advice would be to get a plumber in. A lot can go wrong very quickly...

 

[Riley]

Yep :iagree: it's a safety device so will need to be reinstated correctly

 

[Simon F]

but if you are going to do the job,
best to drain as much as needed and refill.

or better still
if the system needs cleaning you could refill with a cleaner then after a week flush out refill add inhibitor, all new and clean