Increase in boiler pressure when central heating is on.

[alana]

Dear readers - I am not a plumber but do have a bit of technical savvy to seek your help and take your advice. Following problems with my Linear 28 boiler with a blocked expansion vessel pipe last winter I was advised by Vokera to undertake chemically flush the system. I am now planning to do that but on swithing on the heating system I note that the pressure in the boiler rose from 1.5 bar (normal) to 2.5 bar. Can you advise a) Should I ignore this or b) Is it signs of a more serious defect requiring attention from a specialist.

Thank you for your on these matters.

 

[SimonJohns]

This can be normal and I wouldn't worry about it

 

[AWheating]

as your heating warms up and the volume of water in the system gets hot it expands and the pressure will rise. This is normal unless the rise is excessive and causes the prv to run.

 

[Gascat]

Well if it rises gradually as the heating warms up this is perfectly normal for the reeason stated by AW above. if on the other hand it rises very quickly then it may indicate an issue with the expansion vessel, for which you would require someone with experience of working on boilers.

 

[maks_rt_011]

Your expansion vessel seems to be flat or you got blockage in the pipe going to it , Try to pump it up to 1.5 p. (using same pump as for car tyre). If won't help then mean you got blockage again. you can ignore it now , but when it start reaching 3 bar then safety valve will start to drop some water out and you 'll be loosing pressure constantly when heating in use.

 

[AmritPedersen]

If you know the EV pipe is blocked, then isolate boiler, drain, then remove & clean pipe. That'll get boiler working. However, what caused the blockage? A flush would probably be a good idea, followed by inhibitor. I'd recommend a MagnaClean (or imitation) on general principle. A flush will not get all the sludge out, but a magnetic filter will trap this, year on year. Well worth the cost!!!

 

[alana]

Thanks everyone foe your advice. As a new member to the forum I am surprised at the speed of your responses and delighted with the consistency of your replies. Until next time

Best regards

Alana