CH airlock or something else?


Hi guys,
Having a weird problem with what I believe is an airlock in my CH system. It's a pumped system, and the rads aren't collecting much air (been bled daily for about 3 weeks now) and appears to be working ok, but the flow and return pipes to the boiler appear to be making a noise
like trickling water.
With the boiler output control cranked up, it occasionally blows out the cut-out switch, so I've backed it down to half way successfully, but the trickling noise remains.
When the boiler stops (and the pump cuts out too), I can hear water almost sloshing back to the boiler making me think I have an airlock. It occasionally 'phuts' and pops when it's been running for a while (again, making me think there's air in the heat exchanger).
I've got a drain off cock on one of the pipes to the boiler, and when I
drained and refilled the system, it did let out quite a lot of air before running water came out at a constant rate, but there's no drain off on the other pipe (the flow I think). Perhaps trapped air in that part of the system?
The only bleed valves not on the rads are on the pump (no air coming out) and a capillary valve on a high point on the system (again, with negligable air coming out).
Any suggestions?
Cheers,
Paul
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Check your header tank to see if it has water in it.
| Hi guys, | | Having a weird problem with what I believe is an airlock in my CH | system. It's a pumped system, and the rads aren't collecting much air | (been bled daily for about 3 weeks now) and appears to be working ok, | but the flow and return pipes to the boiler appear to be making a noise | | like trickling water. | | | With the boiler output control cranked up, it occasionally blows out | the cut-out switch, so I've backed it down to half way successfully, | but the trickling noise remains. | | | When the boiler stops (and the pump cuts out too), I can hear water | almost sloshing back to the boiler making me think I have an airlock. | It occasionally 'phuts' and pops when it's been running for a while | (again, making me think there's air in the heat exchanger). | | | I've got a drain off cock on one of the pipes to the boiler, and when I | | drained and refilled the system, it did let out quite a lot of air | before running water came out at a constant rate, but there's no drain | off on the other pipe (the flow I think). Perhaps trapped air in that | part of the system? | | | The only bleed valves not on the rads are on the pump (no air coming | out) and a capillary valve on a high point on the system (again, with | negligable air coming out). | | | Any suggestions? | | | Cheers, | | | Paul |
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