Hi All
bit lost on an issue with an old back boiler - Open Vented.
Hot water circuit on Gravity (right side) and Central Heating pumped (left side)
Glow-worm Boiler on Ground floor not sending hot water to Cylinder (coil) on 1st floor. Boiler stat cuts out boiler on detecting over-boil.
However, Central Heating works fine when turned on.
Boiler F&E Tank Feed is free and works perfect when re-filling required.
Cylinder Flow and Return pipes (short horizontals) have been removed and mains water circulatd thru cylinder so no blockage in the coil.
Mains water circulated thru Boiler Flow and Return pipes (long verticals) so can't be blockage there.
The only way I can force hot water up the Boiler Flow pipe is when a slow stream mains water hose is attached to the draincock, fitted on Return pipe near the Boiler. This way Boiler stays on longer whilst heating up incomming cold water. Heated water rises up the flow pipe all the way to F&E Tank and does not enter the Cylinder coil.
Thinking about it, hot water will not entre cylinder coil and finds its way down via the Return pipe. Why I think? Because slow stream mains water hose on draincock must be sending 50% water to Boiler and 50% up the Return pipe, so no chance gravity hot water circulation can form.
When slow stream mains water feed via draincock is removed you would think that would kick-start the desired circulation but no joy. The whole circuit cools down. Boiler goes back to old tricks of cutting out due to over-boil.
Air-lock in the Coil?? - I tried slackening upper union (on Flow pipe) near the Cylinder but no joy.
Could I have some Advice on how to remedy this please. There must be a trick I am missing.
Thanks.
bit lost on an issue with an old back boiler - Open Vented.
Hot water circuit on Gravity (right side) and Central Heating pumped (left side)
Glow-worm Boiler on Ground floor not sending hot water to Cylinder (coil) on 1st floor. Boiler stat cuts out boiler on detecting over-boil.
However, Central Heating works fine when turned on.
Boiler F&E Tank Feed is free and works perfect when re-filling required.
Cylinder Flow and Return pipes (short horizontals) have been removed and mains water circulatd thru cylinder so no blockage in the coil.
Mains water circulated thru Boiler Flow and Return pipes (long verticals) so can't be blockage there.
The only way I can force hot water up the Boiler Flow pipe is when a slow stream mains water hose is attached to the draincock, fitted on Return pipe near the Boiler. This way Boiler stays on longer whilst heating up incomming cold water. Heated water rises up the flow pipe all the way to F&E Tank and does not enter the Cylinder coil.
Thinking about it, hot water will not entre cylinder coil and finds its way down via the Return pipe. Why I think? Because slow stream mains water hose on draincock must be sending 50% water to Boiler and 50% up the Return pipe, so no chance gravity hot water circulation can form.
When slow stream mains water feed via draincock is removed you would think that would kick-start the desired circulation but no joy. The whole circuit cools down. Boiler goes back to old tricks of cutting out due to over-boil.
Air-lock in the Coil?? - I tried slackening upper union (on Flow pipe) near the Cylinder but no joy.
Could I have some Advice on how to remedy this please. There must be a trick I am missing.
Thanks.