Combi Boiler - Help !!!!!!!!!!!

[BigGar]

Hello
Have just moved house into a place with a brand new combination boiler and new radiators. They were fitted prior to me moving in. Built the pressure up using the mains cold water inlet and the thing fires up nicely. After about 30 minutes though the pressure has fallen to zero and the thing cuts off.

Anybody know much about these things ???? Have had to use the cold water to re-pressurise the system 3 times now which can't be normal. Any tips ??? Realise there is the possibility of a leak but any other tips ?? The radiators last night were making loud noises up o 2 hours after the boiler had been swtiched off. Could this be air pockets and could this cause the boiler pressure to drop ????

HELP!!!!!!!!!
Thanks!

 

[rwalters]

It could be a leak in the heating system somewhere, rad valve or more likely, it is probably your pressure release valve. It only takes a small drip to loose pressure. Check outside the house near the boiler and you will see the pressure release outlet. It should not be dripping.

Hope this helps.

Richard

 

[BigGar]

Thanks Richard. Want to get to the bottom of this! Just finsd it strange that there may be a leak when evrything is brand new!

Thanks

 

[rwalters]

It maybe a faulty pressure vavle, we had the same problem a few months back. Been working fine for years and then all of a sudden, all pressure went. On investigating outside the pressure overflow pipe was dripping, not much, but enough to drop the pressure.

However, it may be a leak internally, as it only takes a small leak to drop the pressure it may not be as noticable as a damp patch on a wall or ceiling so I would go round whereever you can and check visually for any wet patches under rads. Also, check the bleed valves on the rads as one of these not closed properly will cause this problem and sometimes you will not see a damp patch under the rads if the rad is hot as any small amount of water leaking for the valve will simply steam off before it gets to the floor.

Hope you find it.

Regards

Richard

 

[BigGar]

Bled the radiators last night and turned the water pressure up. When the pressure reached 1.5 bar I stopped and continued to bleed the radiators. The gauge went back down to practically nil. Followed the same procedure again and drained all air out (or so I thought)and got to stage where just water was coming out so tightened up with radiator key. Boiler fired up fine. Within 25 minutes the gauge had dropped to zero again and the boiler had cut off. No water appeared to be going out through back of boiler via pressure relief valve. Again this morning there is a load of air in the radiators so there must be air pockets somewhere. Further confusion has arisen from fact that no air or water is in the kitchen radiator so maybe there is a blockage there (?) or perhaps I need to open the valves in that area. Am stuck!

 

[sljmew]

Shut off the valves at the kitchen radiator, take it off and give it a good flush out with water.

 

[rwalters]

To loose that pressure so quickly you must have a leak somewhere, I cannot believe that it is simply air in the system.

Do any of the CH pipes go underground or in the floors especially in the ground floor where water leaks under the floor are harder to spot.

Air should not be getting into the system as the pressure in the system will push water our, not normally draw air in.

Good luck.

Richard

 

[Galvanised]

you will lose a hell of a lot of pressure when bleeding rads...ive got a bosch28cdi and when i took a rad off to paint behind i re-pressurised the system 3 times and bled ( furthest to nearest to combi ) before the i could finally settle the pressure at 1 bar..
open all the valves for the system and pressure it up to 1.5 bar and start bleeding furthest to nearest and you should be ok..

 

[BigGar]

Hello everyone

Had someone come around last night and we are now convinced that there is a leak somewhere. A firm is coming tomorrow to take a look so hopefully it will be fixed then. Major hassle really when you consider that part of the reason we moved there was because it had a brand new central heating system. The boiler is guaranteed but I doubt the plumbing is! Gutted!!!

 

[BigGar]

HAd a huge leak fixed on Saturday morning!!!!! HAs made things a lot better but the pressure is very slowly starting to drop and I've had to pressure up again a couple of times. Whilst the pressure would drop to zero in about 20 minutes before now it has lost about 0.5 bar in about 10 hours. Is this normal when the system is being used for the first time ?

 

[BigGar]

Had a major leak repaired on Saturday. Before the leak the pressure would drop to zero in about 20 minutes. Now pressure is slowly starting to drop and will drop about 0.5 bar in about 8 hours. Does this mean that I may have another leak or could it be that there may still be a bit of air in the system and that this is usual when the system is new ?