Boiler problems

[diggerjones]

I've got a combi oil boiler. It's been playing up so tonight I changed the nozle. Now I can't get rid of the air. The tank is half full. The boiler needs to suck it up about a metre. Never had this problem before. Any bright ideas

 

[V8Druid]

I've got a combi oil boiler. It's been playing up so tonight I changed the nozle. Now I can't get rid of the air. The tank is half full. The boiler needs to suck it up about a metre. Never had this problem before. Any bright ideas

presumably you disconnected the supply line from the pump ?? ... is there no bleed port on the pump? is your tank line connection drawing air ?

 

[diggerjones]

Yes I disconnected pump to put new nozzle on and clean electrodes. I've been bleeding it from the bleeding screw. There's a continuous stream of air coming. There's a length of clear pipe before it enters the pump where you see the air. I'm stumped

 

[pettsy]

Does it come direct from the tank or through a tiger loop?

 

[TiltyShaun]

Yes I disconnected pump to put new nozzle on and clean electrodes. I've been bleeding it from the bleeding screw. There's a continuous stream of air coming. There's a length of clear pipe before it enters the pump where you see the air. I'm stumped

On our boiler it is a pain to bleed at the bleed screw. Have to do it at the injector.

 

[diggerjones]

Does it come direct from the tank or through a tiger loop?

Straight from tank

 

[diggerjones]

It's like it's getting air in, but can't be or oil would be escaping. It was OK before I took the pipe off

 

[pettsy]

Obvious question but did you isolate any valves? Tried old nozzle back in it?

 

[diggerjones]

Obvious question but did you isolate any valves? Tried old nozzle back in it?

No not touched any valves. Why would the nozle make any difference?

 

[pettsy]

Was just thinking could be a faulty nozzle.

 

[V8Druid]

It's like it's getting air in, but can't be or oil would be escaping. It was OK before I took the pipe off

the pump will only suck fluid if it has fluid in it .. if it's dry it has no chance... can you fill the pump and maybe your clear length of hose from the bleed port with a few syringe-fulls of kero?

 

[Stroppymonkey]

What boiler do you have? Clear tube makes it sound like it might be an HRM or a Grandee wall hung affair?

 

[V8Druid]

Was just thinking could be a faulty nozzle.

I have had that in the past .. but did semi function, just dripped/over fuelled

 

[Stroppymonkey]

the pump will only suck fluid if it has fluid in it .. if it's dry it has no chance... can you fill the pump and maybe your clear length of hose from the bleed port with a few syringe-fulls of kero?

If tank below burner then it must either have a tigerloop/deareator or a non return valve on the line.
Start at the beginning. Check tank filter clean and free of water. Check any other external filters ditto. Check the Firevalve hasnt tripped. Suck oil through to flexi using a suction pump to ensure clean air free supply. If you have changed the nozzle you need to be checking combustion readings once it fires which means a flue gas analyser.

 

[V8Druid]

No not touched any valves. Why would the nozle make any difference?

fuel has probably run back down supply line and emptied pump when nozzle line, etc., disconnected

 

[Stroppymonkey]

We use these to pull Kero through. Have adapted them with some lathed bungs that take BSP fittings so we have a vacuum gauge and iso valve on them.

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[Stroppymonkey]

fuel has probably run back down supply line and emptied pump when nozzle line, etc., disconnected

Should have NRV on line if suction system.

 

[V8Druid]

We use these to pull Kero through. Have adapted them with some lathed bungs that take BSP fittings so we have a vacuum gauge and iso valve on them.

??????

 

[Stroppymonkey]

??????

Sorry dropped the link.. remedied now!

 

[diggerjones]

fuel has probably run back down supply line and emptied pump when nozzle line, etc., disconnected

The pump is working. Its pulling fuel up, but with a load of air. Think these boilers have a built-in none return valve.