I have a Halstead Ace combi boiler. If I've ran DHW for period of more that 5 minutes (eg bath), once the burner has stopped, there is escape of water from the auto air vent tube, accompanied by gurgling sound. This only occurs when the CH is off. If the boiler switches over to CH immediately the DHW stops then no problem.
Short draws of hot water seem ok
Occasionally after the escape of water and CH has not turned on the "overheat Thermostat" comes on.
Third observation is that the pressure guage for the CH drifts drops each time the water escape occurs. We have had the pipework and radiators checked for leaks several times and there appear to be none.
Could the pressure loss be related to the escape of water via the air vent.?
On a previous service the engineer suspected that the expansion vessel might be the cause. Apparently it needed "re-pressurised" and this was done.
any thoughts, thanks
Donald
Short draws of hot water seem ok
Occasionally after the escape of water and CH has not turned on the "overheat Thermostat" comes on.
Third observation is that the pressure guage for the CH drifts drops each time the water escape occurs. We have had the pipework and radiators checked for leaks several times and there appear to be none.
Could the pressure loss be related to the escape of water via the air vent.?
On a previous service the engineer suspected that the expansion vessel might be the cause. Apparently it needed "re-pressurised" and this was done.
any thoughts, thanks
Donald
