Hi there
I have a Worcester Bosch Greenstar system boiler. On turning on the central heating this week I noted the pressure was a little below 1 bar so I topped it up to the 1 bar mark. Fired up the heating again and noted later that the pressure gauge was well into the red - around 3 bar, but the PRV did not go off.
From a previous life I knew that this could potentially be the pressure/expansion vessel. I called out British Gas, chap found very low pressure in the vessel, re-pressurised, all seemed okay EXCEPT after he went I noted the pressure creeping way back up into the red with the C/H on (I think he only checked it with the hot water on). I thought that maybe he over-pressurised with too much water as I think he mentioned it being set to 1.5bar when cold.
I decided to leave it all off and when I got home later the cold pressure had dropped again to below 1. Topped it up, put the C/H on and the pressure was again back in the red. I checked the PRV pipe outside - bone dry. I cannot find any noticeable leaks at rad valves, pipe elbows etc.
Does this sound like a faulty expansion vessel, and would a faulty expansion vessel cause the cold pressure to drop even if the PRV valve had not activated (so no water being discharged outside)??
I'd appreciate any advice from the experts before I take action.
Many thanks!
I have a Worcester Bosch Greenstar system boiler. On turning on the central heating this week I noted the pressure was a little below 1 bar so I topped it up to the 1 bar mark. Fired up the heating again and noted later that the pressure gauge was well into the red - around 3 bar, but the PRV did not go off.
From a previous life I knew that this could potentially be the pressure/expansion vessel. I called out British Gas, chap found very low pressure in the vessel, re-pressurised, all seemed okay EXCEPT after he went I noted the pressure creeping way back up into the red with the C/H on (I think he only checked it with the hot water on). I thought that maybe he over-pressurised with too much water as I think he mentioned it being set to 1.5bar when cold.
I decided to leave it all off and when I got home later the cold pressure had dropped again to below 1. Topped it up, put the C/H on and the pressure was again back in the red. I checked the PRV pipe outside - bone dry. I cannot find any noticeable leaks at rad valves, pipe elbows etc.
Does this sound like a faulty expansion vessel, and would a faulty expansion vessel cause the cold pressure to drop even if the PRV valve had not activated (so no water being discharged outside)??
I'd appreciate any advice from the experts before I take action.
Many thanks!
