where to read pressure gauge on pressurized system

phester28

I have a pressure gauge in the hot press which is the highest point in the system. There is also a gauge at the boiler downstairs.

We have had 2 floods because of other issues regarding our plumbers from the same company. But hopefully now the main leaks issues have been solved.

the fill point and pressure gauge is in the hot press upstairs and on the zoned side. there is a bypass valve fitted but we have no idea what pressure it is set to.Plumber did not know what to set the bypass to. If I bump the cylinder zone valve there is (so far) always a little air gurgling noise and the auto air vent hisses. I have done this 2 times so far.

There appears to be around 0.5 bar between up and downstairs gauges at idle,cold and pump not running

when is the correct time to fill to 1bar

shane0007

Set the pressure from the downstairs gauge as this is the true system pressure, well as near as true as you can get.
The automatic bypass valve should be set at pros 0.4 bar but this is really dependent upon the head of the pump and the distance the valve is from the pump. If it is only a 5m head pump, I would set the ABV at around 0.2 - 0.3 bar.
Bumping the zone valve? Hissing from AAV is telling you there is still air in the system and if the zone valve is on the flow pipe to the cylinder, then the route for air to the AAV is blocked. Open the zone valve and check system for air.

Always fill/top up system when the system is cold and take the reading from the boiler pressure gauge.

jimjimt

If you are filling your system and air is coming out of the air vent regularly you may still have a leak in your system.

How often are you topping up the pressure ?

How often is coming out the air vent ?

phester28

well its just been re-commissioned had a bad leak on a relatively new fitting (an older plumber used push on elbows) and they did not like the increased pressure.

last night I bled each rad in the house. I found 2 that had a reasonable amount of air in them.

I have topped up 2-3 times yesterday.

I am hoping that it is residual air that makes it into the coil on the tank but can not get to the air vent as it is on the return.

The next few days will tell allot I guess.

At what point would you say I have a leak a top up every 3months or so?


It makes me nervous that the new system has some of its elbows and tees below concrete and now my floors have been finished. The feedback from the company is that sometimes with old systems you just cant find some small leaks.

I have access to all other fittings in the house and so far all are bone dry at room temp so am I being fobbed off if it is still not holding pressure. I have not yet paid the company for installation

jimjimt

Push fittings can take a good as pressure as any other fittings if installed properly.

Have you an old system with new pipe work and new boiler installed ?

If you got your pipe work "re-commision" from a leak that had been fixed as such you should not have to be bleeding radiators or be concern about getting air out of pipe work and on the return pipe or other. It should have been done and checked.

About twice a year would not be uncommon to top up even at that you can be sure their is the tiniest of a weep somewhere. Every 3 months would be a small leak or large weep which would be extremely hard to find un less over ground.

All air should be gone out of your system in 24 hours/overnight, pumped , bled or through auto air vents. If you have to bleed or try and get air out of the pie work the next day again it is time to have a chat with your plumber.

A plumber should also know how to set a Auto Bypass Valve.

phester28

yes it is a new system with some old pipework. Upstairs rads and cylinder are copper.

A bit supprising that they ran the new pipework (qualplex) pipe in pipe and told me that it is not necessary to insulate any of the pipework. It is below ground level.

Last night I checked the cold pressure and it still at 1 bar so fingers crossed I have no more leaks/weeps