Hope you can help, I woke up last week with no heating. I have a Baxi Bermuda 551 back boiler with gravity fed hot water and central heating is pumped. I still have plenty of hot water coming from taps but no rads (upstairs and downstairs), I have five pipes that are connected to the boiler: 2 X 28mm that both feel hot, 1 X 15mm that feels cold and 2 X 22mm, one with the pump on in the up direction that feels hot and one with the valve on with that feels cool, I called a plumber in who advised me it was a non return valve on a 22mm pipe. I drained the system down and replaced the valve in the same direction as the previous valve. Still no heat in the rads, have replaced and vented the pump. Still no heat in rads.I then put a Fernox sludge remover in the F & E tank, ran for a day then drained and vented again, to my surprise when I started draining the system the the top rads started getting warm. I refilled the system and turned the heating on and it was cold again. I'm confused that both the 22mm pipes seem to be coming from the boiler,thought it would make more sense that there ws one from (flow) and one to (return)the boiler, please advise.
Thnaks for the reply, pump is pumping well. I have just replaced the pump the other day, turned heating on and stat up and it's wirring and when I put it on highest setting it wirrs more. I've turned pump off and there's no heat in the pipe above pump then turned back on and there's instant heat. Can you explain why both 22mm pipes, one with pump (hot) and one with check valve (cool) are both in the up flow direction please? Thanks
Called in a plumber to find the problem, then did it yourself. Now it still doesnt work, aint you the clever one.
are there valves on the pump ?? if so one aint open !!the non return will be to stop the water going to the rads when the hot water is on , the pump will overcome the non return when its running assuming its the right way round , what type of non return have you fitted ?? is there water in the pump ?? have you bled it properly ? open the large chrome screw in the middle and shut when water starts coming out, if the pumps running and the boilers on i suspect the pump valve
Can't see the purpose of a non-return valve on the heating system but irrespective of that you need to ensure the pump and the valve are in the same flow direction as it sound like one is pushing against the other. Either that or a pump valve is turned off.
Thanks for all replies, <u>All hours:</u> Thanks for that comment, plumber friend was going on holiday, advised me before he had to fly off. <u>Doing a bit:</u> There are no valves on the pump (Grundfos 15-50), water is flowing though because when I vented pump water dribbled out of the vent screw hole and pump is working because I could see centre spindle rotating. Plumber advised it was faulty (as above), I replaced it in the same flow direction as original. <u>Big Jumbo:</u> I was told by my plumber friend that the check valve was to stop water creeping up the central heating system in the warmer seasons. the type of check valve I bought is a Comap dbl check valve DZR.
you dont need a double check valve !! this will probablly be enough resistance to stop the pump completely, you need a gravity check valve!!
I meant that I consider the valves to be more of a nuisance than they are worth, but that's a purely personal thing. Not being smart but are you sure there are no screw-slot type fittings either side of the pump?
completely, you need a gravity check valve!! Didn't know it was a double check valve until your question, thanks. Does it make sense to you that the pump flow direction is pointing up and so is the check valve on other pipe? Excatly the same as the original fittings.
there's your problem then, if valve is pointing up and pump is on other pipe, it needs to point down towards the boiler.
think you guys may be right about the valve, thanks for that. I'll go and buy another, would appreciate a list of what the valves maybe called as from experience I could get there and be confused, wouldn't be hard to be honest. Thanks again
you can take the valve off, then the pump can go any way, only draw back is the upstairs rads will work when you only want hot water. so turn them off at the rad valves.
WOW it worked thanks to all for the advice. I took the valve out and replaced with straight 22mm coupling and the heat is very welcome. Thanks again to all.