Hi all. I have a problem with my 6 year old Vokera Synesti 35 Combi Boiler. I have provided as much information as to the story to date. Sorry if it’s a bit long !
Day 1. Came home to find the red warning light flashing with an error code of 4 – Low Water Pressure. Checked the gauge and it was sat on 0.2 bar. Checked with the missus to see whether she had been bleeding radiators (again lol) and no, she hadn’t touched them after the last time she did it 4 weeks earlier and caused the low pressure warning. So I refilled the system back to 1.2 bar (1 bar +0.2 bar for 2 metres from top of boiler to highest pipe run). Reset boiler and all okay.
Day 2. On the morning the pressure gauge was at 0.5 bar and had to go to work so didn’t touch it. By the evening it was down to 0.2 bar. Refilled the system back to 1.2 bar and went leak hunting round the rads and pipework in roof space – nothing found there. Switched on the system for the evening and the pressure gauge went up to around 1.8 bar when hot. When it switched off that night I rechecked the pressure gauge and it was down to 0.6…. I refilled the system back to 1.2 bar and noticed a leak from the bottom of the boiler. Took the casing off and traced the leak to the Automatic Air Vent behind the pump. I surmised that the valve was faulty and was venting air and water though I had not seen any evidence of water leaking from the boiler until the 3rd refill?
Day 3. Visit to Plumb Centre for a new AAV and fitted it. 10 mins, job done I thought…..nope! The first mistake I made was to use the PRV to partially drain the system down - well it said to use it in the Vokera Installation manual ! Up to this point I had not checked for a leaking PRV by the way-thinking that the AAV was the obvious culprit. Anyway, refilled the system to 1.2 bar and heating switched on pressure reached around 2 bar max and when switched off we were down to 0.2 bar…. Of course the PRV had been leaking since I used it which could have thrown the red herring into the system…
Day 4. New PRV fitted (thanks Plumb Centre) and system refilled to 1.2 Bar. Switched on heating and kept and eye on the gauge and watched it climb all the way round to 3 bar before I switched the system off. This took around 10 mins from a cold system. The system is now off and the pressure has gone gradually back down to 1.2 or a little below but the PRV may have operated briefly. It’s not leaking now so the new valve is okay. Over the last few hours since it has been off the gauge has been stable or slightly down as the water cools.
I am slightly stuck in checking the pressure of the Pressure Vessel at the moment – I have just about reached the valve and pressed the pin briefly – air heard escaping but no water seen. Because the boiler was mounted on a bare wall that has now been insulated and plaster boarded I have a little work to do to get sufficient clearance to get my pump and gauge in. This I hope to achieve tomorrow evening. List of swear words ready....
So my question is – am I right in suspecting the Pressure Vessel is down on pressure and causing the rapid rise in pressure when the heating is turned on or do you think the problem is elsewhere? Any other fault finding tips please? I shall let you know what happens next !
Day 1. Came home to find the red warning light flashing with an error code of 4 – Low Water Pressure. Checked the gauge and it was sat on 0.2 bar. Checked with the missus to see whether she had been bleeding radiators (again lol) and no, she hadn’t touched them after the last time she did it 4 weeks earlier and caused the low pressure warning. So I refilled the system back to 1.2 bar (1 bar +0.2 bar for 2 metres from top of boiler to highest pipe run). Reset boiler and all okay.
Day 2. On the morning the pressure gauge was at 0.5 bar and had to go to work so didn’t touch it. By the evening it was down to 0.2 bar. Refilled the system back to 1.2 bar and went leak hunting round the rads and pipework in roof space – nothing found there. Switched on the system for the evening and the pressure gauge went up to around 1.8 bar when hot. When it switched off that night I rechecked the pressure gauge and it was down to 0.6…. I refilled the system back to 1.2 bar and noticed a leak from the bottom of the boiler. Took the casing off and traced the leak to the Automatic Air Vent behind the pump. I surmised that the valve was faulty and was venting air and water though I had not seen any evidence of water leaking from the boiler until the 3rd refill?
Day 3. Visit to Plumb Centre for a new AAV and fitted it. 10 mins, job done I thought…..nope! The first mistake I made was to use the PRV to partially drain the system down - well it said to use it in the Vokera Installation manual ! Up to this point I had not checked for a leaking PRV by the way-thinking that the AAV was the obvious culprit. Anyway, refilled the system to 1.2 bar and heating switched on pressure reached around 2 bar max and when switched off we were down to 0.2 bar…. Of course the PRV had been leaking since I used it which could have thrown the red herring into the system…
Day 4. New PRV fitted (thanks Plumb Centre) and system refilled to 1.2 Bar. Switched on heating and kept and eye on the gauge and watched it climb all the way round to 3 bar before I switched the system off. This took around 10 mins from a cold system. The system is now off and the pressure has gone gradually back down to 1.2 or a little below but the PRV may have operated briefly. It’s not leaking now so the new valve is okay. Over the last few hours since it has been off the gauge has been stable or slightly down as the water cools.
I am slightly stuck in checking the pressure of the Pressure Vessel at the moment – I have just about reached the valve and pressed the pin briefly – air heard escaping but no water seen. Because the boiler was mounted on a bare wall that has now been insulated and plaster boarded I have a little work to do to get sufficient clearance to get my pump and gauge in. This I hope to achieve tomorrow evening. List of swear words ready....
So my question is – am I right in suspecting the Pressure Vessel is down on pressure and causing the rapid rise in pressure when the heating is turned on or do you think the problem is elsewhere? Any other fault finding tips please? I shall let you know what happens next !