… praying to the plumbing God, Bob
Pictures and layout details attached, so be patient.
21 year old oil fired system in pretty good nick. I noticed some minor pumping over from the vent (occasional burst of water, and the odd dribble). Didn’t think much of it as I was about to replace the heating pack, clean the system with F3, and check the cold feed all at the same time.
I noticed the start of some magnetite in the cold feed, so isolated the pump, cut out the infected pipe and replaced (circled Red on pic). At the same time, I cleaned out the tank, all the rads and then flushed through the whole system with F3. After I fitted the new 2 port valves, I added a Fernox TF1 Omega filter in the return pipe for a belt and braces solution.
All went back well, system works a treat……..except the pumping over is still there.
The boiler is in the kitchen, the pipework goes into the loft (Bungalow) along the loft space for around 2 metres, then into a 22mm air separator with vent on top, cold fed tee afterwards (approx. 8cm between the vent and cold feed). Then drops down around 1.5 metres into the airing cupboard and enters the pump (original pump since 2002, no known issues from previous owner). After which into heat / water valves and off under the floor to the rads. From floor returns up through the airing cupboard via the TF1 then along the loft space back into the boiler (there is an AAV fitted on this return, and on the top feed coil to the hot water, both of which were replaced as they really help bleed the system when refilled!)
Distance from vented elbow to water level in tank is 460cm. I’ve tried adjusting the ballcock to lower the tank water lever, turning the pump (Granfos Alpha variable speed) on its lowest setting, the pump over still happens. I’ve looked down the pipework into the bottle air separator with a borescope looking for blockages, nothing found.
Property next door is exactly the same, the same system, the same layout, the same original parts. It doesn’t pump over.
Ideas on a postcard?
Pictures and layout details attached, so be patient.
21 year old oil fired system in pretty good nick. I noticed some minor pumping over from the vent (occasional burst of water, and the odd dribble). Didn’t think much of it as I was about to replace the heating pack, clean the system with F3, and check the cold feed all at the same time.
I noticed the start of some magnetite in the cold feed, so isolated the pump, cut out the infected pipe and replaced (circled Red on pic). At the same time, I cleaned out the tank, all the rads and then flushed through the whole system with F3. After I fitted the new 2 port valves, I added a Fernox TF1 Omega filter in the return pipe for a belt and braces solution.
All went back well, system works a treat……..except the pumping over is still there.
The boiler is in the kitchen, the pipework goes into the loft (Bungalow) along the loft space for around 2 metres, then into a 22mm air separator with vent on top, cold fed tee afterwards (approx. 8cm between the vent and cold feed). Then drops down around 1.5 metres into the airing cupboard and enters the pump (original pump since 2002, no known issues from previous owner). After which into heat / water valves and off under the floor to the rads. From floor returns up through the airing cupboard via the TF1 then along the loft space back into the boiler (there is an AAV fitted on this return, and on the top feed coil to the hot water, both of which were replaced as they really help bleed the system when refilled!)
Distance from vented elbow to water level in tank is 460cm. I’ve tried adjusting the ballcock to lower the tank water lever, turning the pump (Granfos Alpha variable speed) on its lowest setting, the pump over still happens. I’ve looked down the pipework into the bottle air separator with a borescope looking for blockages, nothing found.
Property next door is exactly the same, the same system, the same layout, the same original parts. It doesn’t pump over.
Ideas on a postcard?