no water pressure from boiler

[bobonacus]

Hi,

I replaced the circulator pump in my system and I now have no pressur from the boiler!

I shut off the valves either side of the pump before replacing.

I took the pump out and opened the valve from the boiler ( I confirme it was opening by putting a screwdriver up the pipe!) but nothing cam through. There is no header tank in the loft, the water feed pip disapears off down through the floor boards and I can't trace it.

The boiler is a potterton PrimaB.

Questions:

1. I don't understand where the feed is coming from, does anyone kno anything about this type of boiler, can't seem to find any info on th net. I assume it is a sealed system?

1. There are two pipes that go straight up from the boiler and stop a a little pot thing with what looks like a car tyre valve dust cap o the top, not sure what they are

[image: for any help

Rober

-- bobonacus

[andrewpreece]

The little pot with the Schraeder valve thingy is the air separator: I believe the knurled cap should be unscrewed a turn or two to allow air venting.

I'm not too sure what your other problem is. Are you saying your pressure guage is reading zero? If so ( i.e. you have a sealed pressurised system ), then you need to get some water into the loop. This is usually achieved with a 'filling loop'. Depending on your boiler, this may be a braided pipe with a valve at either end goig from your mains cold water feed pipe to the CH flow ( or return ) pipe. Alternatively, it could have been remved ( it is supposed to be to stop leaks into the mains water system, so you'll need to fid one and connect it up, or perhaps you will have a built in filling loop in some discreet position beneath your boiler, and there will be a couple of 'tiny valves that need opening with specail keys ( a bit like raiator keys ). Bottom line is, you need to open two valves to allow mains water into your CH loop to pressurise it ( and then close them again ).

Andy.

[Tony]

the things above your boiler are auto air vents , make sure the caps ar

not screwed down tight , or the air wont get out ,

from looking at your picture I would say you have a system boiler not combi , therefore there must be a cold feed to the system somewhere , probabl in the airing cupboard , unless its a very new system , it wil probably be a 15mm pipe , you could trace it from the heat/expansio tank in the roof space , you should have two tanks , a big one and little one , its the little one , check the tank hasn't emptied with the arm from the ball valve stuck i the up position , if it has , easy fix , free the arm . if the tank is full , you may have a blocked cold feed , very common this will mean cutting the cold feed where it joins the system unblocking the pipe , and re-joining the pipe , there will be som water , so be carefull , a rad valve changing kit is usefull for doin this , if your very lucky someone may have put a valve in just abov where the cold feed joins the system , if not , put one in when you cu the pipe . this is just a guess , as i cant tell for sure without being there but the way to tell if your cold feed is blocked , is to put a drain o the system , and see if the h/e tank starts topping itself up , if i does the cold feed is ok , hope this helps

-- Tony

[IMM]

They are automatic air vents.

[IMM]

Auto air vents are for filling/commissioning purposes only. Once the system is free of air the tops are to be screwed down. Combi instructions actually state this a smost have integrated. When the auto air vent is open hydrogen from internal corrosion may escape. If there is hydrogen in the sytem it will make the tops of rads cold, and that is a sign that the system requires proper attention not just releasing it and refilling.

[Tony]

thats all very well and good , but that isn't a combi boiler

-- Tony

[IMM]

I know that and I never said it was. I gave the e,g., of combi instructions. It is clear this boiler did not come with auto air vents.