New Boiler - How much air in the system should I expect?

[Bobbbyboy]

Evening All,
Our old boiler recently gave up the ghost so bit the bullett and our local heating engineer installed a Baxi Solo 18HE condensor. The house is a 4 bed detached about 10 years old with a vented system with a mix of 15mm standarad and microbore pipes to the radiator.

The boiler was fitted about two weeks ago now, but I am still having to bleed air from the towel radiator in our ensuite bathroom every 5 days or so. There's not masses of air but enough to collect and to create a dripping sort of noise from the rad when its heating up.

Further info is that once the boiler was fitted it was run for 3/4 days with a cleanser (Fernox F3 I think) and then was flushed multiple times before being filled up with inhibitor Fernox F1.

Obviously weve got air in the system - how long should it take to bleed out the air from the complete draindown and refill? We had a lot mor air in the system with the old boiler b ut it used to kettle really badly which seem to create a lot of air/gas.

Any help welcome.... I'm currentlythinking Fernox F4 as Im sick of bleding the rads, but may be a bit rash with a new boiler and microbore? Or am I being a bit impatient?

 

[Agile]

What do you think F4 will do for you?

Why dont you trust your boiler installer to answer your questions about the new installaton?

Tony

 

[Bobbbyboy]

He seems to shrug it off when I speak to him as being normal saying that air will always collect in the highest point, which I am fully aware of. My question was after a complete draindown and refill how long should I need to rebleed? and how long is too long to keep manually bleeding?

Thanks for your response but I didnt say I didnt trust my installer or his opinion, just looking for a second one that's all. I paid him to replace the boiler, which is what he has done.

 

[Agile]

And what do you think F4 will do for you?

I normally advise that on a typical system there will be a little air for about a week if heating is used at least twice a day.

I have this feeling that you are being "overactive" !

Rads should ONLY be bled if they are showing the need for it because they are cold at the top.

You should not be bleeding just to see if any air is there!

Tony

 

[Terry lambert]

There is obviously a problem, this isn't normal.

I would check that the order from the boiler was boiler vent cold feed. Is the open vent the correct height above the f & e tank ( normally 450mm )
Is the f & e high enough above the boiler?
These dimensions will be in the manual

Pump speed too high?

What I'm checking for above is whether the vent is pumping over. This boiler doesn't have a pump over run, and so when the clock/ stat stops calling for heat look in the loft, does water come out of the vent pipe?

If all above is correct you may have a leak / weep somewhere, probably on the ground floor as you obviously havnt seen any signs of a leak on ceilings. Check rad valves/spindles ect

 

[Terry lambert]

After re-reading your post, I would give it a little longer.

When you fill a system with fresh water it has air in it which when heated is given off, this will dissipate, let it settle.

 

[dcawkwell]

Vented boiler pants.
Should have had a system boiler and sealed system.

Most likely the boiler is piped in wrongly and drawing air into the system.
Or pumping over into header tank.

Get someone else.

 

[Bobbbyboy]

Many Thanks to all for your input.

Tony - I think I am being a little overactive as you put it, but I am not "looking for air", the top rung of the towel radiator is cold and I am bleeding it because of that. I am needing to do that very few days now.

I will be patient and see if it settles down over the next few weeks.

 

[dcawkwell]

Many Thanks to all for your input.

Tony - I think I am being a little overactive as you put it, but I am not "looking for air", the top rung of the towel radiator is cold and I am bleeding it because of that. I am needing to do that very few days now.

I will be patient and see if it settles down over the next few weeks.

Can you light the air coming out of the radiator? If so you have hydrogen
being generated in the central heating.

 

[ianmcd]

Dont bleed the system with the pump running make sure you switch the CH&HW off at the programmer before opening the bleed screw of your towel rad