Air in the system

[tfheung]

I have an unvented hot water/heating system. The system come with the house, which are both just over 3 years old. Every summer, when it is warm, I always have problem with the heating. Either going off completely or a while ago, the pump would not stop in accordance with the timer. I have sought the advice here and apparently the PCB of my Potteron is sh*t. However, as it is working most of the time and it cost so much for the PCB, I thought I just leave it. (Not to mention a thread recently on the problem of blewing fuses after a new PCB.)
Another problem is air getting into the system. Whenever the heating come on, there is a lot of bangs near the boiler and/or the pipes. Which is pretty scary. I have tried to let the air out from the radiators and letting more water into the system - through a double valves control near the hot water tank. This used to do the trick. However, it doesn't work this year. The bangs keep coming back and I have let in a lot of water already. I cannot see any obvious leak apart from some seepage near the mains, near the hot water tank. Any idea where the water has gone and how can I trace it?

Somehow, it wasn't a problem in the winter when the heating is on all the time. Only when the themo-control cut it that I have so many problems.

Many thanks in advance.

 

[Slugbabydotcom]

Sounds like a right can of worms there. Wouldn't be a suprima would it?

Could be a few things going on there but heres some ideas

Banging noise is because water is overheating in the boiler!
This could be caused by a problem with the boiler stat or poor water flow so check pump is working and perhaps turn the speed up a bit.
Could be a blockage somewhere / sludge.

Pressure vessel could need renewing or pumping up. What are the readings hot and cold?
Have you checked the PRV to make sure the water isnt escaping there.

I cannot see any obvious leak apart from some seepage near the mains, near the hot water tank

If this is from part of the system it is an obvious leak!!!