Powermax 155x not firing for central heating

[Hot&Cold]

I'm hearing lots of bubbling water sounds when I call for central heating and the pumps starts.

is the auto air vent open and functioning ?

so I had to pump air back in the vessel again

was there any air charge in the 18l expansion vessel ?

There is a ton of gurgling noises coming from the boiler, pipework and rads,

The pump is now moving water and air around,lots of air as you had it part drained.It will gradually settle down keep bleeding the rads and the auto air vent will clear air from the top of the boiler.

When refilling the system do I need to let the boiler cool before introducing cold water to build the pressure back up?

Top up water pressure at any time.

The pump looks like the original powermax badged pump.usually single speed pump but if it has a speed selector ensure its on max speed.

The pump may be turning but we dont know how much water its shifting

 

[muffking]

is the auto air vent open and functioning ?

Is that the black valve to the left of the CH pump? Not sure how to test it other than sticking my ear to it and it does sound noisier in that general area.

was there any air charge in the 18l expansion vessel ?

Yep. I try to keep the vessel at around 0.8 Bar before using the loop to top up the water pressure.

The pump is now moving water and air around,lots of air as you had it part drained.It will gradually settle down keep bleeding the rads and the auto air vent will clear air from the top of the boiler.

Great stuff. I'm pretty confident that all the air is now bled out of the rads, although there is still air in the system somewhere as I can hear it moving around.

Top up water pressure at any time.

The pump looks like the original powermax badged pump.usually single speed pump but if it has a speed selector ensure its on max speed.

The pump may be turning but we dont know how much water its shifting

I reckon it was installed in 2001 as that's when the house was built and the pump may well be the original and possibly on borrowed time, just like the rest of the boiler


The current state of play is that the boiler pressure is dropping after its been run, possibly as the air is vented.

Can you confirm that my process of re pressurising the system is correct. When the boiler pressure is low (say below 0.5 Bar) I pump the vessel to 0.8 Bar and then use the loop to take the total pressure to around 1.5 Bar.

 

[Hot&Cold]

Is that the black valve to the left of the CH pump?

The aav is on top of the boiler just under the top lid.It must be working to some extent as there is no mention of lockout during this current event.The aav may just be venting slowly which is ok ish.

Yep.

if the air charge in the expansion vessel was the same then it should be ok.

although there is still air in the system somewhere

Some systems take an age to clear all the air,just bleed the rads when the tops are cold.

he boiler pressure is dropping after its been run, possibly as the air is vented.

Hopefully just air,have a look into the black plastic tundish,stick a finger in it and see if any water is passing if so the prv is letting by.

When the boiler pressure is low (say below 0.5 Bar) I pump the vessel to 0.8 Bar and then use the loop to take the total pressure to around 1.5 Bar.

No need to pump air into the 18l expansion vessel everytime (could do more damage than good). just top up the pressure via the filling loop

 

[muffking]

The aav is on top of the boiler just under the top lid.It must be working to some extent as there is no mention of lockout during this current event.The aav may just be venting slowly which is ok ish.

I couldn't see through to the back very well, but like you say the lockout has never come on.

if the air charge in the expansion vessel was the same then it should be ok.

Some systems take an age to clear all the air,just bleed the rads when the tops are cold.

Hopefully just air,have a look into the black plastic tundish,stick a finger in it and see if any water is passing if so the prv is letting by.

No water in the tundish, it's as dry as a nuns crotch

No need to pump air into the 18l expansion vessel everytime (could do more damage than good). just top up the pressure via the filling loop

ok. As soon as I asked the question I thought I'd better stop pumping air in the vessel otherwise the pressure may mainly consist of air. Now I'm just topping the water up when it drops. This appears to be getting less each time


The resolution to the problem seems to have been combination of getting the ch pump going again, pushing water through the system and getting the air out of it.

In the mean time thanks for all of your help and the others who replied on here.
I had left a voicemail for my local plumber 2 days ago who hasn't got back to me, so without all your help I would be in a freezing cold house and spending the nights shutting myself in the living room with the gas fire on.

 

[andytw]

Looks like your flow switch is leaking. I replaced the poor gaskets with "14MM ID X 4MM METRIC NITRILE 70 RUBBER O-RING" from eBay.

 

[muffking]

You may be right as there looks to be some corrosion around and below it, but I dare not even look at it the wrong way in case it spits it's dummy out and goes completely.

I am still losing pressure though. I keep adding water to 1.5 Bar, but it drops back down to pretty much 0Bar in no time. I can't see any leaks and there is no air in the rads. Where could all this water be going?

 

[muffking]

Panic over. Found a loose join when I noticed that it was raining in the garage