Hi,
I have a situation where late in the evening (10pm as HW goes off and no Heat demand) the boiler continues to run and will run overnight unless I stop it. If I turn HW relay on/off it then stops it. This is an intermittent issue but probably 50%.
Configuration.
- Worcestor Bosch CDI 30 boiler with integrated pump.
- Y Plan config with 3 port valve. Recently replaced the head - https://www.screwfix.com/p/honeywell...pression/273fv
System appears to be wired correctly as per https://www.diynot.com/diy/attachmen...ler-jpg.91360/
Things already checked
- 3 port valve was old and a little "sticky". Replaced it with new head as per above.
- We had a Sundial Wiring Centre which heating engineer has seen issues with previously so has been replaced by a standard Drayton wiring box.
When I look at the voltage on the feed going back to the boiler there seems to be a floating voltage (around 12v) after the Heating demand has gone. e.g.
- With HW or CH demand feed = 240v
- When HW only has been on and then switched off feed = 0v
- When CH only has been on and then switched off feed = about 12v. There is a small capacitor (0.1uF) already installed across the boiler feed/neutral and if I remove this the floating voltage moves from 12v to 60v.
This article here talks about a snubber capacitor - https://ensupport.getconnected.honey...language=en_US
I presume the 12v is still enough to drive the boiler to continue to run the pump?
Has anyone else experienced this type of issue? Is it a case of getting a larger capacitor and can anyone advise size?
Thanks
I have a situation where late in the evening (10pm as HW goes off and no Heat demand) the boiler continues to run and will run overnight unless I stop it. If I turn HW relay on/off it then stops it. This is an intermittent issue but probably 50%.
Configuration.
- Worcestor Bosch CDI 30 boiler with integrated pump.
- Y Plan config with 3 port valve. Recently replaced the head - https://www.screwfix.com/p/honeywell...pression/273fv
System appears to be wired correctly as per https://www.diynot.com/diy/attachmen...ler-jpg.91360/
Things already checked
- 3 port valve was old and a little "sticky". Replaced it with new head as per above.
- We had a Sundial Wiring Centre which heating engineer has seen issues with previously so has been replaced by a standard Drayton wiring box.
When I look at the voltage on the feed going back to the boiler there seems to be a floating voltage (around 12v) after the Heating demand has gone. e.g.
- With HW or CH demand feed = 240v
- When HW only has been on and then switched off feed = 0v
- When CH only has been on and then switched off feed = about 12v. There is a small capacitor (0.1uF) already installed across the boiler feed/neutral and if I remove this the floating voltage moves from 12v to 60v.
This article here talks about a snubber capacitor - https://ensupport.getconnected.honey...language=en_US
I presume the 12v is still enough to drive the boiler to continue to run the pump?
Has anyone else experienced this type of issue? Is it a case of getting a larger capacitor and can anyone advise size?
Thanks
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