Automatic filler

dashcamdanny

What is the proper procedure for setting these to the correct pressure?

It was zero yesterday night. Brass screw at the rear was nearly all the way out. So was the black knob. All the way out. Anti clockwise. System was full of air and gorgling.

So I screwed the rear brass screw in halfway and the black knob half way.

Now, as you can see. I'm way over. Nearly 3 bar.

It's a bungalow with 2 zones and oil boiler.

Is there a proper way to set it?

Should it be cold with the boiler off or boiler on? Nothing happens fast with it.

Lenar3556

Close the black valve by turning fully clockwise. This stops incoming water.

Release some pressure at a radiator bleed valve, so as you have approx 1-1.5 bar when the system is cold.

Did the pressure gauge only increase when system warmed up? If so this may point to an expansion issue, rather than over filling.

A domestic system should only require top up once to twice a year maximum.

dashcamdanny

https://www.boards.ie/discussion/comment/121275857#Comment_121275857

We bought the house last year. Second hand. Heating was never right. I blead the rads yesterday . Lots of air. Zero pressure. Expansion tank had zero pressure. Gave it a few pumps with a foot pump. No water leaking from it.

I started messing with the auto filler, and probably made it worse. It's the rear screw that I really need to set properly

I just drained off the pressure at the pressure release valve. As it was starting to pop anyway.

Now. System is full. Sitting at 1 bar. But slowly increasing pressure again with heat on.

What is the correct procedure?

I have done a fair bit of diy on heating before, change rads, drained systems and so on not completely clueless. I hope..

Lenar3556

https://www.boards.ie/discussion/comment/121275898#Comment_121275898

Expansion vessel not charged will be the source of many issues, so get that sorted first. (Sometimes it’s better to just replace it.)

1.5 bar of air pumped into your expansion vessel (do this with system water pressure at zero) and then fill system to 1.5 bar using your filling valve.

On the filling valve - Tightening the brass screw increases the pressure, turning it anticlockwise reduces it. But I wouldn’t be too bothered by that. Use the black valve to allow enough water in to reach 1.5 bar then turn it off. We need to know if the system is loosing pressure, so no more ‘automatic’ filling!

It’s best not to use the pressure relief valve as a manual drain - they have a tendency to leak afterwards.

How big is the house? What size expansion vessel have you? Pressure increase in the region of 1/2 a bar or so is normal when the system is hot. Much more than that points to an expansion vessel issue - faulty or undersized.

dashcamdanny

Thanks. I believe it's a 12ltr tank. 13 rads. 4 bedroom bungalow.

I think I'm going to replace the auto air vents, pressure relief valve and may as well replace the expansion tank as I'm doubtful it's all in working order. I think the screw fix tank comes pre charged with 1.5 bar of nitrogen

The air vents are covered in crud. And so is the relief valve.

I don't think there has been any inhibitor added for 10 years. Very hard water area.

Lenar3556

Sounds like a good idea.

12 litre expansion vessel may be on the small side. I would up to it to 18 litres when replacing.