Boiler still working even at zero pressure

thor

I have noticed loads of threads about boiler pressure and leaks and I have found my vaillent eco max boiler contradicts most of what I have read.
For months and months(if not years) the pressure meter has indicated a pressure of zero, less than 0 millibars. This has not had any effect on the ability of the boiler to deliver a good stream of hot tap water and heating for the whole house. It was for this reason I never did anything about it as I reckoned if it was not broke.......
Anyway after reading the messages here I decided I had better up the pressure to the green are shown on the meter. I did this a couple of weeks ago but the pressure has now almost returned to zero. I don't see any evidence of leaks(of course that does not mean there isn't one) but as none of this is having any adverse effects should I be concerned.

Pyewacket338

Sounds to me like the pressure gauge is faulty.
I'd wait until the system was cold, if the gauge reads zero, I'd open the bleed valve on the highest radiator in the system and see how much pressure it had, if the water spurts out with good pressure, then your system should be fine, you can either leave it alone..... although knowing the pressure is a good thing, if it does go over the safe limit the pressure relief valve should kick in. You could replace the gauge on the boiler or fit an external gauge, the latter probably being the cheaper option (the only problem with having an external fitted gauge is the central heating circuit valves have to open to check the pressure in the boiler, unless you're removing the boiler, you'll probably never close these valves anyway)

sickparrot

Check that water isn't slowly leaking out of the pressure relief valve (should be a pipe going outside the house). Our vaillant boiler would fire with no pressure in, but it's not ideal.

bockster

i have an ecotec plus, if i press the " - " button it displays the pressure in bar on the lcd display. yours may be similear???