Help! Central heating works but hot water doesn't!

[2815davidtester]

Hi all,

I'm new to the forum but hopefully there is someone out there who may be able to help.

Our central heating is working fine but our hot water supply is not working as it should. Over the last few days it has become less and less warm, to the point this evening that it was too tepid to put our kids in for their pre-bedtime bath.

The boiler works fine, the heating seems warm as usual and there doesn't seem to be any interruption on the supply. The water comes out in same quantity, but the warm has been getting progressively cooler.

On checking the tank in the cupboard, all the pipes leading up to it are scaldingly hot, but 10-15 cm away from the tank they are cool.

We have an oil fired Boulter Camray Compact boiler which seems perfectly in order, if a little old. It is firing properly on the timer and on demand.

Having spoken with a friend, I have checked the tank thermostat, turning it from cool to hot, but cannot hear any click. The same friend recommended turning off the heating and turning on the hot water. This I have done, and the pipe into the tank seems to have warmed up now.

Can anyone shed any light on what the problem might be?

Also, can anyone recommend a reliable heating engineer/plumber in the Waterlooville/Portsmouth area?

 

[secret squirrel]

Think it may be one of two problems, cylinder stat is not working or you have a 2/3 port valve issue.

You need to get an electrical tester to test whether the cylinder stat is calling for heat when its required. Also check whether the two/three port valve is working.

This should isolate what is at fault then replace the broken bit

 

[2815davidtester]

Thankyou ever so much for the quick reply and advice.

Only problem is, I'm not entirely sure what you are talking about! Should I therefore get an expert in, or can you give me a translation into basic laymans English?

 

[secret squirrel]

If you hang about I'm sure someone here can explain things a bit clearer than I have but in fairness I'd consider getting someone in to repair it. The problem is if you have no idea (not wanting to be insulting) even if you get the information you may struggle replacing the part thats broken.

 

[2815davidtester]

You're right, I don't have a good enough knowledge of the system. I have a basic knowledge and am reasonably competent, so I was hoping that it was a case of simply replacing an easily identifiable part. Thanks for your help anyway, I'll see if there is input from anywhere else and start looking for a suitable plumber.

 

[piperdave]

sounds like a 2/3port(zone) valve issue to me aswell,it will look like this or similar , but i would advise getting a competent person in to change it definately .

 

[2815davidtester]

thankyou, I recognise the part in the picture but it's beyond my ability. I'll get someone in!

 

[justlead1]

Hi. If the system is filled with water via a small cistern which may well be in roof space? Check that the ball valve is working (it may be stuck in off position ) if so give it a shake, If it starts running water? give it a few minuets and check result on heating/hot water system. Good Luck

 

[Kip]

He has plenty of water to taps, so its not the cistern. The problem is that its just not getting hot, so something somewhere is not allowing to c/h water to pass through the coil in the cylinder, either a 2/3 port valve is not operating or the cylinder stat is knackered not sending the message to the port valves telling them to open. OR there's a blockage which sounds closer to it to me as you say the water has been getting cooler and cooler for a while now. Slow flow i think, could now be completely blocked in the coil

 

[archiedale]

Agree with KIP, repair it properly once...

 

[stevetheplumber]

He has plenty of water to taps, so its not the cistern. The problem is that its just not getting hot, so something somewhere is not allowing to c/h water to pass through the coil in the cylinder, either a 2/3 port valve is not operating or the cylinder stat is knackered not sending the message to the port valves telling them to open. OR there's a blockage which sounds closer to it to me as you say the water has been getting cooler and cooler for a while now. Slow flow i think, could now be completely blocked in the coil

if theres no water in the f and e tank you will have water at the taps but no circulation through cylinder coil which is often the highest point on the system was a very common problem on coventional systems with gravity hot water dont see it so much on fully pumped systems but it does happen and is often combined with a blocked cold feed

 

[WHPES]

I had a similar case when the spindle in the motorised valve was getting stiffer and stiffer and could hardly open at all by the time I was called out.