Heating system low pressure

awec

The water pressure in our heating system is low, just slightly above 0 bars. In the past when this has happened I've gone to a valve by the hot water tank that has the pressure gauge on it, loosened it to let water in until it's up to 1 bar and then close it again (which is what the plumber told me to do).

However, now I can open this valve fully and nothing happens.

The valve has a black screw knob on one side and on the opposite side there looks to be a fitting that requires a hex key or something (I've never touched this).

Any ideas how to increase the pressure, or am I at the stage of just calling a plumber out?

Wearb

They can fail.

Open the valve and give the body a few gentle taps of a stout screwdriver handle. Failing that make sure that you have a good feed to the valve (no upstreamvalves closed). Bear in mind that it could be a faulty gauge.

John.G

A few photos would help.

awec

https://www.boards.ie/discussion/comment/121908903#Comment_121908903

I guess they can be temperamental!

After opening and closing it about 5 times, the 6th attempt seems to have done the trick and water flowed in again. I guess something was stuck (I'm guessing this is why you suggested the taps)?

As a side note, is it normal to have to do this semi-regularly? I would say I'll need to do it again in about 6 months.

Wearb

Topping up twice a year isn't a problem. Just check that you a properly functioning expansion vessel.

Having to "fight" with your auto fill valve is unusual and I'd suggest replacing it at some convenient time in the future, perhaps summer time.

Seventy Plus

Why is it in a sealed system that you have to every so often let in water so as to bring it up to above 1

Wearb

https://www.boards.ie/discussion/comment/121958329#Comment_121958329

Leaks. Sometimes so small that they evaporate.

Leaking pressure relief valve, often due to wrongly sized, pressure setting or faulty expansion vessel.

Any more than small top-ups a few times a year can cause corrosive damage.