Heating ok No hot water

[jimmin]

Just found this site and looking for help! I have an Stelrad/Ideal CH system open vented fully pumped with gravity feed and flow (quoting out of installation book) system is about 10years old. Getting heating ok but no hot water can any one suggest anything to try before I have to get professional help? Header tank is full and gravity flow pipe is not hot although when I bleed it it becomes very hot for short time.

 

[oilman]

......fully pumped with gravity feed and flow.......

I know it's in your manual, but it's a contradiction. It's either fully pumped, or it's not. If it's the CH that's pumped and gravity HW, that's ok, but it means it's not fully pumped.

There is probably a blockage in the pipe, or the non-return valve (if you have one) is not working correctly. The blockage could be in the pipe, unlikely, more likely at the joint coming out of the top of the boiler. You will have to disconnect it to see. While its off you can try pushing some water round the HW circuit with a hose.

 

[jimmin]

Hi thanks for quick response did manage to get pipe feeding hot water tank hot where it was entering tank, did this by draining gravity feed pipe. Unfortunately didn't maintain heat and water still getting only luke warm

 

[oilman]

You need to look at the joint coming out of the boiler.

 

[Southview]

Hi, me and my neighbour have had a similiar problem this week, the boilers went in at the same time 10 years ago and they were both Le Blanc combi boiler systems anyway back to problem, the hot water in my house suddenly went luke warm the same as my neighbours, he had a new boiler installed "costly", previous to the boilers playing up though we had the water board messing with the pressure on the mains system all of a sudden the water was running at a faster rate, so I have since reduced the pressure at the incoming mains tap and the water is now hot again, but is running at a lower rate and I am unable to increase the mains pressure as it becomes luke warm again, possibly my boiler is on the way out ? at least I have got some spares from the neighbours old boiler before he bins it, waste not want not , hope it helps.
And if anyone has an Idea on increasing mains pressure without losing temperature would like to no.
Cheers Allan

 

[oilman]

Hi Southview, it would be better to start another topic otherwise this one gets to be a mix-up.

........so I have since reduced the pressure at the incoming mains tap....

You have a pressure reducing valve on your mains? I suspect you have adjusted the flow rate, not the pressure.

It sounds like you have a combi boiler and a sealed system, which is different from jimmin's system.

Your problem is probably a scaled up plate heat exchanger.

If you want to follow this up, please start a new topic so others can help.

 

[jimmin]

Success!! took little time but everything seems to be ok water hot hot hot, guess it was air in system and draining from gravity feed seems to have done the job. Thanks for comments very impressed with speed of replies, great site thanks again.