Help with central heating

knightstyle

right, spent the afternoon round there. The water is coming from the mains pressure regulating valve, I checked the filter and it was clear. So I have ordered a new one, over £40 plus VAT, and have a plumber coming on Friday to fit it.
Thanks for all the advice.
This is the faulty valve. http://i1040.photobucket.com/albums/b403/mycaravan/Photo%20on%2008-03-2017%20at%2011.03_zpsnjvqdpqz.jpg?t=1488901748

knightstyle

Just another question, I refitted the white expansion tank as the builders had tried several times and each time it fell after a short while!
It only had a small bracket and was very heavy, is this normal?

keith969

knightstyle wrote: »

Just another question, I refitted the white expansion tank as the builders had tried several times and each time it fell after a short while!
It only had a small bracket and was very heavy, is this normal?

It shouldn't be. Mine's a 12L capacity one and it weighs a couple of kilos. If the diaphragm's gone and its filled with water, then it would be heavy...

Alex1983

they get heavy when the vessel isnt charged enough. Get the plumber to test the air pressure in it. If it is split you can replace the diaphragm without having to replace the whole expansion vessel. You undo the bolts on the bottom of it and pull the rubber bag out. When he tests the air pressure of it if he gets water out it is probably split.

knightstyle

Thanks, I will get it checked, what causes the diaphragm to split?

southcoastrgi

My god what a mess, you won't find a diaphragm just replace the expansion vessel if needed, the vessel will tell you the charge on the side but it's likely to be around 5 bar, the pressure gauge you are reading is nothing to do with the multiblock that gauge is the pressure in the central heating, that pump is going to fail as well fitted like that

knightstyle

Thanks, why will the pump fail, it has been in for 8 years. It was fitted the wrong way round at first and the thermostatic valves didn't work properly but they fixed that after a year of complaining.

Just to add, if you look closely you will see that the immersion heater has a cable coming from it, this is normal 2.5t/e used for house wiring, not the heatproof it should be and as there is no connection point for it my DD has to plug it in at the top of the stairs laying it across the floor.
This was done by the "qualified" plumbers sent round by the builders during the first year to give her hot water after 4 weeks of "waiting for parts" The word cowboys does not begin to describe them!