I have a Boilermate A Class OV store and recently drained down to swap a radiator, after refilling the hot water goes cold after 30 seconds but if the tap flow is reduced the temperature rises. Central heating is fine
What I’ve tried:
I have swapped the boilermate DHW pump and heat exchanger
I’ve checked the water level in the F&E tank which is fine
I have released some water from a rad downstairs to check if the F&E tank water level would drop which it did and it started refilling the boilermate so can exclude a blocked feed.
I have slowly backfilled from a rad downstairs to see if this will push the air out and can see the water level in the F&E tank rise
I’ve drained the system down and refilled 4 times
The only bodge fix that works is too open the vent bleed screw on the DHW pump when the pump is running and the hot water tap opened.
As soon as I do this the boilermate starts making noises, similar to sea waves hitting the beach along with the odd gurgle noise so I can only presume air is in the boilermate which is released when I open the vent screw as hot water is pulled from the hot tank by the pump.
However I’ve done this numerous times for approx 20 mins at a time until the noises stop which fixes the issue but the problem keeps coming back the next day and air is back in the tank.
I’ve tried venting with the pump turned off which doesnt work, so I’m wondering if venting whilst the pump is running is causing air to suck into the system through the pump so I’m chasing my tail or is it just a matter of continuously venting numerous times until all of the air is out of the system?
I have seen YouTube videos suggesting to clear an airlock on an OV system by putting mains water down the vent pipe in the F&E tank but I’m unsure how and where the air would escape to if the vent pipe is blocked with mains water?
I’m tempted to drain down again and refill the complete system by backfilling through a rad rather than through the F&E tank as a last resort
Looking for advice as I’m running out of ideas
What I’ve tried:
I have swapped the boilermate DHW pump and heat exchanger
I’ve checked the water level in the F&E tank which is fine
I have released some water from a rad downstairs to check if the F&E tank water level would drop which it did and it started refilling the boilermate so can exclude a blocked feed.
I have slowly backfilled from a rad downstairs to see if this will push the air out and can see the water level in the F&E tank rise
I’ve drained the system down and refilled 4 times
The only bodge fix that works is too open the vent bleed screw on the DHW pump when the pump is running and the hot water tap opened.
As soon as I do this the boilermate starts making noises, similar to sea waves hitting the beach along with the odd gurgle noise so I can only presume air is in the boilermate which is released when I open the vent screw as hot water is pulled from the hot tank by the pump.
However I’ve done this numerous times for approx 20 mins at a time until the noises stop which fixes the issue but the problem keeps coming back the next day and air is back in the tank.
I’ve tried venting with the pump turned off which doesnt work, so I’m wondering if venting whilst the pump is running is causing air to suck into the system through the pump so I’m chasing my tail or is it just a matter of continuously venting numerous times until all of the air is out of the system?
I have seen YouTube videos suggesting to clear an airlock on an OV system by putting mains water down the vent pipe in the F&E tank but I’m unsure how and where the air would escape to if the vent pipe is blocked with mains water?
I’m tempted to drain down again and refill the complete system by backfilling through a rad rather than through the F&E tank as a last resort
Looking for advice as I’m running out of ideas
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