Grant Vortex ECO Utility 21-26. After 3 years use on just now winter start up the factory installed Caleffi PRV (10bar !!!) fractured where it is screwed into the top of the outfeed and so emptied the system water (with Fernox) over the boiler and the control box. There was steam from the boiler room - first reaction was to to knock off the mains and close the cold feed to stop the system refilling.
After clearing up and blanking off the PRV (open system so pointless to fit a PRV) then the Riello RDB2.2 ECON 70-90 LockOut neon (marked LED1 on the pcb !!) came on immediately at power on and did not go out after Reseting. It went out when Reset is pushed (and the fan stops) but came on again after releasing and the fan restarts. The fan motor ran from a power on but there was no spark up after 12 secs. There was oil supply OK. I checked the photocell disconnected measured 3M 'ish dark falling to 5-9K in light which from other posts looked OK.
I presume the Fernox is alkali and hence conductive and so was giving a low resistance across the photocell input causing the LockOut at power up so the PCB was brush washed in distilled water and all air blasted away and pcb dried so that should no longer be a problem.
Lo and behold - problem solved.
The fracture looks like it had been there for a long time but the O ring held the seal and it just finally failed as the boiler temp rose. It was into an iron adaptor - I think it is bad practice to mix brass and iron where the brass is stressed because of differential expansion rates but anyway it looks like it was overtightenned.
Any one else had PRV failure like this ??
Why would they fit a 10 bar PRV ?? - the radiators / pipes would blow well before that I would expect - and anyway on a open system max pressure can only be the height of the header tank so no use for a PRV.
After clearing up and blanking off the PRV (open system so pointless to fit a PRV) then the Riello RDB2.2 ECON 70-90 LockOut neon (marked LED1 on the pcb !!) came on immediately at power on and did not go out after Reseting. It went out when Reset is pushed (and the fan stops) but came on again after releasing and the fan restarts. The fan motor ran from a power on but there was no spark up after 12 secs. There was oil supply OK. I checked the photocell disconnected measured 3M 'ish dark falling to 5-9K in light which from other posts looked OK.
I presume the Fernox is alkali and hence conductive and so was giving a low resistance across the photocell input causing the LockOut at power up so the PCB was brush washed in distilled water and all air blasted away and pcb dried so that should no longer be a problem.
Lo and behold - problem solved.
The fracture looks like it had been there for a long time but the O ring held the seal and it just finally failed as the boiler temp rose. It was into an iron adaptor - I think it is bad practice to mix brass and iron where the brass is stressed because of differential expansion rates but anyway it looks like it was overtightenned.
Any one else had PRV failure like this ??
Why would they fit a 10 bar PRV ?? - the radiators / pipes would blow well before that I would expect - and anyway on a open system max pressure can only be the height of the header tank so no use for a PRV.
