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central heating / immersion problems

Postby batsey » Fri Aug 21, 2009 4:12 pm


I'm trying to help my 87 year old neighbour who is having problems with her heating / immersion heater. I am not a qualified anything and the information below is the best I can do!

The gas boiler is an Ideal Mexico floor standing, Stelrad group, super CF55 open fuel gas boiler.

The immersion [url][/url] as seen in the link an indirect cylinder.

sequence of events : 1. June the boiler was serviced and cleaned, no problems since installation from new.
2. a week later the radiators upstairs came on with water heating only.
3. a week after this she became ill with the heat and the engineer came back and turned off the valves on all the upstairs radiators. (not thermostatic ones - old ones - some need replacing)
4. 2 weeks later I found her freezing as the weather changed and they turned on the upstairs radiators again and told her the problem was that she didn't have the thermostat in the hall set high enough (it was on 70 they said it should be on 80+)
5. weather changed and she once again over heated, she went to help the aged to advise her what to do, they recommended a plumber.
6. Plumber told her it was the pump and promptly changed it saying that the rads needed flushing out.
7. nothing has changed. I told her to reduce the time she had the water on to see if it made a difference down to 3 hours am and 2 hours pm.
8. I had occasion to speak with the original engineer and he told me the problem was a valve, which was possibly in the boxed wall in the kitchen, but that the owner of the company did not wish to do it as it would cause a mess. I asked if I were to take down the wall what did I need to look 4 he explained.

I have today taken down 3/4 of the stud walling to find no valve at all. More over the pipes leading from the boiler to the immersion directly above are cold (1 luke warm, but I think this is from the heat from the pilot light). I asked if I could look in the airing cupboard. It was boiling hot! the water at this point had been off for an hour.
From the attached link I can confirm the following.
1.Drain cock - [color=green]?? don’t know what I was to look for here?[/color]
2 Incoming cold feed - [color=green]cold[/color]
3 Return to boiler - [color=green]red hot[/color]
4 Flow from boiler - [color=green]red hot[/color]
5 Heat exchanger
6 Immersion
7 Hot feed to taps – [color=green]hot up to the point it reaches the vent pipe[/color]
8 Vent pipe - [color=green]hot[/color]

I noticed the immersion was set at over 180 deg F and have turned this down to 143 deg F today.
I have also reduced the hot water to an hour and a half in the morning and an hour in the evening. As a temporary stop gap.
at no point have I found any valves either upstairs or downstairs.
The boiler I am told is in great shape and doesn't need replacing. (She could not afford this anyway).
The engineer has told me that if I can find the valve, he will come FOC after work and give it a tap/replace it for her.
Does anybody have any ideas where this could be. If this is infact the problem, or if I should be looking else where?
Thank you so much
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Postby humperdink » Sat Aug 29, 2009 6:51 pm

sounds like the 3 port valve(three pipes coming out of it) or two port valve sticking open - it would need to be found, - do you know where the pump is as it may be close to that. Or could be under the floor. It is not a problem with the immersion though. good of the guy to come back f.o.c. when you find it though
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Postby htg engineer » Sat Aug 29, 2009 7:17 pm

Can your neighbour have central heating ON without the hot water being ON ? if yes then there'll be a 3 port valve somewhere, the actuator may need changing.

If she cannot have central heating only ON, then it's a gravity system and upstairs radiatior heating is natural, especially with older systems when primaries have limescale build up.

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