additioinal radiator in loft conversion-problem

[hartlepaul]

We recently converted our loft space into another bedroom, we built a cupboard up there to hold the cold water tank and the smaller heating expansion tank. Both tanks are in the same place pretty much as they were before sitting on the floor.
We then added a 600mm radiator by tapping into the flow and return from the floor below. The radiator bleeds fine and heats the loft room well but after a while it fills with air again, this looking back is kind an obvious fault. I'm looking to replace the boiler with a more efficient unit in the new year so now's the time to resolve my issues. We have a pump boosted shower running directly from the tank so we'd like to keep that but solve the heating problem in the loft.
Is it just a case of lifting the expansion tank above the height of the radiator or would i need to lift the tank also? Is there no auto air bleed valve I could fit to resolve the issue.
All advice and points of view welcome

Regards

Paul

 

[Whitespirit66]

When you get the new boiler fitted, consider converting to a sealed system. Not a lot of work and saves raising tanks.

 

[Agile]

The F&E tank should be at least 1 m above the top of any rad!

You can convert to sealed. I used to charge just £126 for that.

Tony

 

[Terry lambert]

That's cheap Tony.

Was that including the cost of the vessel, sealed system kit ect

 

[slapper]

That's cheap Tony.

Was that including the cost of the vessel, sealed system kit ect

And whether the Boiler can withstand the increased pressure and does it have a high limit stat?. But I agree that is way too cheap

 

[ALEC1]

Tony is cheap given his knowledge and skill!

 

[Agile]

That was a fully inclusive cost! But it was about 10 years ago.

However, it was normally a "follow on" charge after a boiler repair visit.

Tony

 

[hartlepaul]

Thanks for the info...
Do i need to be looking for a specific boiler to run a sealed heating circuit or is it sealed because of an add on a accumulator or something like that?
do I also need to specify the height the boiler is pumping to to get the best new one for the job?

regards

Paul

 

[Agile]

All current boilers are designed for closed systems.

Any normal boiler will easily circulate heating over at least 4-5 floors.

Tony

 

[Terry lambert]

If your installer recommends a system boiler, you may still need an additional expansion vessel ( he should be able to calculate this)

He may also need to consider the size of the pump and the resistance of the heat exchanger if you have a large property, as some boilers have a high resistance that can use up a lot of the available power of your pump.