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Hi All. I hope you can help me.
We have a 1970's 2 story house with Oil fired heating. The boiler is a Worcester Danesmoor 15/20 DF. (Its the original boiler from 1976).
It is floor mounted in the kitchen in an alcove with the flu / chimney going directly up through the centre of the house.
The HW tank is upstairs in the bathroom and is not directly above the boiler (1 room away).
We only moved in last year and found the F & E tank bone dry. (may be relevant to the issue).
I unseized the ball cock and the tank filled and the heating worked throughout last winter.
In May this year we had builders in and as part of their job their plumber and electrician converted the boiler from Pumped CH / Gravity HW to fully pumped (Honeywell Y plan) and added tank stat and room stat. There is a Honeywell 3 way valve now installed just above the boiler case in the alcove.
Looking at the boiler from the front there are 5 water connections.
1) Top right front (outlet to pump - Originally just CH now CH & HW). Pump sucks from boiler.
2) Bottom right front (Return from HW tank coil)
3) Top right back (original Gravity feed to HW tank coil - now terminated with an Auto bottle vent)
4) Bottom left back (Return from CH pumped circuit).
5) Feed from F & E tank joins 2 just before connection to boiler.
The pump is a 4 speed affair (set to speed 4 - have tried 3) placed within the boiler case and positioned directly in front of the boiler and about 150 mm down from the outlet (1). The pipe routing from the pump goes down and under the boiler before rising up the back and joining the input to the 3 way valve (originally it just joined the heating circuit pipe).
The 3 way valve is obviously connected to the CH & HW circuits.
In the Airing cupboard, the HW in from boiler to the coil used also to connect to the F & E vent pipe. As part of the conversion, the F & E vent pipe has been disconnected and replaced by a 2nd Auto bottle Air vent.
Now to the problem...........
When the boiler starts up I can hear air / water in the pump and also sometimes around the 3 way valve area (3 way valve is just above the boiler case).
To stop the air noise I have to open the little black cap on top of the Auto Bottle vent in the boiler alcove to let the air hiss out. If I open the black cap on the Auto bottle valve in the airing cupboard a similar amount of air hisses out and I can hear the HW tank gurgle.
After 45 mins of running when boiler shuts down (all rads hot and HW hot) I can open the bottle valves again only to find more air hissing out.
This has been happening since we started using the boiler again last month.
Clearly there is air in the system.
Just to confuse, if I run the pump with burner off, no air release from the valves is apparent, temperature is having an effect here some how........?
So questions:-
1) Should the F & E vent have been disconnected and terminated with a auto bottle vent?
2) If no to 1 above, should the vent connect to the top back right (old Gravity HW feed from boiler) connection on boiler where the auto bottle vent in boiler alcove is currently fitted?
3) Can the Auto bottle vents allow air to be sucked in to the system? (one on boiler is on negative side of pump)
4) If no to 2 above, where is air coming from? (no evidence of leaks anywhere)
5) Is it just a case of residual air in the system that requires a good period of time with the black bottle vent black valves open to clear?
For info the system now contains 1 gallon of Fernox inhibitor.
I am not a professional plumber but have a reasonable understanding of how the systems work, so please feel free to talk technical.
Many thanks for any guidance / experience you assist with.
We have a 1970's 2 story house with Oil fired heating. The boiler is a Worcester Danesmoor 15/20 DF. (Its the original boiler from 1976).
It is floor mounted in the kitchen in an alcove with the flu / chimney going directly up through the centre of the house.
The HW tank is upstairs in the bathroom and is not directly above the boiler (1 room away).
We only moved in last year and found the F & E tank bone dry. (may be relevant to the issue).
I unseized the ball cock and the tank filled and the heating worked throughout last winter.
In May this year we had builders in and as part of their job their plumber and electrician converted the boiler from Pumped CH / Gravity HW to fully pumped (Honeywell Y plan) and added tank stat and room stat. There is a Honeywell 3 way valve now installed just above the boiler case in the alcove.
Looking at the boiler from the front there are 5 water connections.
1) Top right front (outlet to pump - Originally just CH now CH & HW). Pump sucks from boiler.
2) Bottom right front (Return from HW tank coil)
3) Top right back (original Gravity feed to HW tank coil - now terminated with an Auto bottle vent)
4) Bottom left back (Return from CH pumped circuit).
5) Feed from F & E tank joins 2 just before connection to boiler.
The pump is a 4 speed affair (set to speed 4 - have tried 3) placed within the boiler case and positioned directly in front of the boiler and about 150 mm down from the outlet (1). The pipe routing from the pump goes down and under the boiler before rising up the back and joining the input to the 3 way valve (originally it just joined the heating circuit pipe).
The 3 way valve is obviously connected to the CH & HW circuits.
In the Airing cupboard, the HW in from boiler to the coil used also to connect to the F & E vent pipe. As part of the conversion, the F & E vent pipe has been disconnected and replaced by a 2nd Auto bottle Air vent.
Now to the problem...........
When the boiler starts up I can hear air / water in the pump and also sometimes around the 3 way valve area (3 way valve is just above the boiler case).
To stop the air noise I have to open the little black cap on top of the Auto Bottle vent in the boiler alcove to let the air hiss out. If I open the black cap on the Auto bottle valve in the airing cupboard a similar amount of air hisses out and I can hear the HW tank gurgle.
After 45 mins of running when boiler shuts down (all rads hot and HW hot) I can open the bottle valves again only to find more air hissing out.
This has been happening since we started using the boiler again last month.
Clearly there is air in the system.
Just to confuse, if I run the pump with burner off, no air release from the valves is apparent, temperature is having an effect here some how........?
So questions:-
1) Should the F & E vent have been disconnected and terminated with a auto bottle vent?
2) If no to 1 above, should the vent connect to the top back right (old Gravity HW feed from boiler) connection on boiler where the auto bottle vent in boiler alcove is currently fitted?
3) Can the Auto bottle vents allow air to be sucked in to the system? (one on boiler is on negative side of pump)
4) If no to 2 above, where is air coming from? (no evidence of leaks anywhere)
5) Is it just a case of residual air in the system that requires a good period of time with the black bottle vent black valves open to clear?
For info the system now contains 1 gallon of Fernox inhibitor.
I am not a professional plumber but have a reasonable understanding of how the systems work, so please feel free to talk technical.
Many thanks for any guidance / experience you assist with.
