No hot water

[carbee]

Hi all

Can I ask you experts out there for some help again please. I have just moved into a property and have no hot water. I have an oil fired system. (Potterton Boiler) When I switch the water on from the timer both water and heating come on even though the heating is switched off. The rads heat up but no hot water. I managed to get a plumber out at the weekend who said it could be the valve which is stuck causing the flow to go to the rads and not the boiler. He bought a new valve but only changed the electronic part (bear with me I'm a woman!) as the valve was working on the old one OK. He switched the water on again, said leave it for a couple of hours and it'll be fine. I'll email you the bill! Still no hot water and rads still heating up when only water switch is on. I have been up into the loft, header tank has water in and ball is working. The tank next to it (expansion tank?) has water in and working OK. Only a little brown discolouration at bottom of tanks. Back to the water tank in the airing cupboard. When I have the water switched on all of the pipes areoung the tank become boiling hot except for the pipe going into the top of the tank and the pipe going into the bottom part of the tank. This bottom pipe is linked to the valve that was changed. AL the pipework to the valve box and the box itself gets hot but the pipe going from the box to the tank is cold. Sorry have tried to explain as best as I can. (By the way I have phoned another plumber and he said it sounds like the pump) What I can't understand is the pipework before and after the pump is boiling hot when touched and there is a noise coming from the pump so it seems to be working - then again I am no plumber. Reason I am posting is I can't get a plumber until 26th May!

Thanks for your help

 

[stem]

Unfortunately without being able to physically examine the system I doubt anyone could offer you definitive advice on here. We could guess like your plumber, and also like him get it wrong!

You don't say what type of system you have, OK it appears to have one (or more?) motorised valves, but there are different types that work quite differently. If you have a single 3 port valve (Known as a Y Plan) it could be as simple as the valve being fitted the wrong way around, although the plumber should have spotted this pretty sharpish, or it could be a wiring fault which may require detailed investigation with electrical test equipment. Unfortunately having just moved in you won't be able to give any history about the system and when it last worked properly or if anything has been changed recently.

In any case, anyone competent with heating systems would have been able to test the valve before replacing it and would have discovered that it wasn't faulty. A proper heating engineer will test the system and find the fault before replacing any components. Your problem shouldn't be too difficult for a decent engineer to find quickly because the fault is always present, it's the intermittent ones that are tricky to solve.

 

[carbee]

Hi Stem

Thanks for your reply. I appreciate it's difficult without seeing the system. Just wondered if there was something glaringly obvious that I hadn't done. Will wait for my plumber to come out!

 

[Hugh Jaleak]

If Radiators are working, then I'd suspect the pump is ok. Can you post a pic of the valve that was changed to help us identify it? There are various possibilities, valve could be stuck open to CH/closed to HW or could be fitted the wrong way round, (If you select CH and switch HW off, what happens?), wiring issue, etc as Stem has said.

Possible if a 3 port valve you could wedge it open to both ports, or even free it off, these should return to HW position when at rest, depending on manufacturer of Valve.

 

[ianmcd]

post some pics of your hot water cylinder (tank) and its controls , if your radiators are heating up its unlikely to be the pump.

 

[carbee]

Thank for your replies. I don't have internet yet either! so hence the delay in replying. I will try what you have suggested with the valves tonight and if no joy I will take some photos and post.

 

[Agile]

Why have you not called back the plumber who came?

Did you pay him?

Tony

 

[carbee]

Sorry for the delay. Just wanted to thank you all for your help. I got a very small hammer! and gave the valve a light tap a couple of times and hey presto! I now have hot water so I think the valve was getting stuck or moving the wrong way so the Central Heating was coming on instead of the water. I know it will need replacing but for now it works. Thanks guys

 

[Agile]

I don't encourage that tool or repair method but if it has worked then it has done what was needed.

Tony