Boiler/hot water problem - advice please

Razor

Hi again,

Ok try putting a towel around the pipe under the AAV, (black cylinder with red bit on top at rear left of airing cupboard), then undo nut under AAV half a turn and give it a little wiggle until water or air comes out, if air you probably have an airlock and the AAV needs replacing if water the 3-port valve is likely kaput.

I'm in Northampton, (E mids) and the water is not particularly hard here.

Does your immersion heater work or have you not tried it as a temp measure?

justontime

Razor wrote: »

Ok try putting a towel around the pipe under the AAV, (black cylinder with red bit on top at rear left of airing cupboard), then undo nut under AAV half a turn and give it a little wiggle until water or air comes out, if air you probably have an airlock and the AAV needs replacing if water the 3-port valve is likely kaput.

I'm in Northampton, (E mids) and the water is not particularly hard here.
So am I

Does your immersion heater work or have you not tried it as a temp measure?The immersion heater will not work either

Thanks, I will try what you suggest and let you know.

BobProperty

plumb1 wrote: »

....Imo you have either a faulty 3 way zone valve(loose paddle inside) or air trapped.
Plus there is no bypass fitted(as i can see) i would recomend you plumber fit 1, and also remove the auto airvent change to manual vent, also lift the botton vent up.

Also the old 22mm pipe adj to the cylinder return does this have a vent?

It is 99.9% unlikely that the cylider coil is blocked, otherwise most of your other heating pipes would be in a worse condition, and would be best to have a chemical flush.

Canucklehead thinks there is a bypass, there's a gatevalve without a wheelhead in picture 1.
This problem is still bugging me. Is the immersion not working a co-incidence? Did it work previously or did the OP almost always rely on the CH system for hot water so the immersion not working wouldn't be noticed?
Is it possible it is a Primatic and whoever altered the CH system didn't notice?
What would happen if the heating coil has broke (i.e. holed or fractured) internally? You wouldn't get a pressure drop, would you?

justontime

Razor, I have to try the actions you suggested in the morning because I have to empty the airing cupboard and take the shelves out to get at the AAV. My arms are too short

Bob, Thanks for your thoughts. I didn't use the immersion very often, but it was working until this problem arose. We have checked the electrics, fuse etc. I can't really answer your other points except to say that the standard of work from the company who fitted my boiler etc was unsatisfactory and had to be corrected shortly afterwards. So it is quite possible that they could have got something else wrong, The company has since ceased trading. As I mentioned earlier, we used to have a back boiler, I don't know if that helps.

justontime

Razor wrote: »

Ok try putting a towel around the pipe under the AAV, (black cylinder with red bit on top at rear left of airing cupboard), then undo nut under AAV half a turn and give it a little wiggle until water or air comes out, if air you probably have an airlock and the AAV needs replacing if water the 3-port valve is likely kaput.

I have now managed to do as you suggested and I just got water (hot water). Thanks for your advice, the plumber is coming again on Thursday, at least I will be able to ask more meaningful questions this time. I am a bit concerned because he didn't do any of the things that have been mentioned here before deciding that the cylinder needed to be replaced, but perhaps I am just being over anxious.

plumb1_2

BobProperty wrote: »

Canucklehead thinks there is a bypass, there's a gatevalve without a wheelhead in picture 1.

If it is ?it is fitted in the wrong possition?Gate valve used to reduce the flow, after it is a tee, 1 branch going to the cylinder and the other i suspect going to the AAV.

BobProperty wrote: »

Is it possible it is a Primatic and whoever altered the CH system didn't notice?
What would happen if the heating coil has broke (i.e. holed or fractured) internally? You wouldn't get a pressure drop, would you?

If it was primatic(its not) the mains feed would blow out the air-bubble and send water into the CWS tank up the feed /expansion pipes from day 1.
If the coil had a small hole, you would get a pressure drop, but the OP has said the pressure is OK.
If it did have hole you would also get the heating system mixing with the stored water making it a Brownish colour.

Razor

I don't think Canucklehead called the gatevalve a bypass, its there to balance the system. We might have been sidetracked by the mention of a blockage.

Try turning just the hot water on at the programmer, does the boiler fire? If not it points to an electrical problem with the cylinder thermostat or motorised valve. Next try putting both hot and cold on at programmer, if you look at the lever in the slot on the valve you will see that you can push it to the end and latch it there does the pipe that goes from the valve to the cylinder get hot then?

justontime

Razor wrote: »

Try turning just the hot water on at the programmer, does the boiler fire? If not it points to an electrical problem with the cylinder thermostat or motorised valve.

Next try putting both hot and cold on at programmer, if you look at the lever in the slot on the valve you will see that you can push it to the end and latch it there does the pipe that goes from the valve to the cylinder get hot then?

The boiler does fire when the heating is turned off and the hot water is turned on

Sorry to be thick, what exactly do you mean by try putting both hot and cold on at programmer?

justontime

Just a few lines to say than you to everyone who offered help with my boiler problem, it is very much appreciated. The plumber came to fit the new cylinder today and we finally have hot water again. He says it was the cylinder being clogged up that caused the problem, but whatever it was it is all working again now. Thanks for the advice about getting the pipes replaced and three way valve repositioned, I asked him about it and he has done that too. It is so good to have hot water again!

BobProperty

Only a couple of questions then, clogged with what? and presumably he replaced the immersion or have you not bothered with one this time?