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Combi Boiler fault finding

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martin perman18/12/2018 18:43:34
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Posted by Alan Waddington 2 on 18/12/2018 18:38:04:

Posted by Howard Lewis on 18/12/2018 18:27:45:

Very interesting!

Our 1973 cast iron boiler must be approaching end of life. (Its had a few thermocouples and the pump impellor has needed reshimming once or twice, so it's a bit like Trigger's broom!)

Is it possible to buy something similar, still, without the complications of condensing, pressure tanks and the like?

All advice gratefully received

Howard

fat fingers again!

Edited By Howard Lewis on 18/12/2018 18:28:33

Sadly not Howard, all gas boilers must now be A rated energy efficient, which means condensing. The latest building reg's also require the fitting of smart controls, with either load compensation or a flue gas recovery system in place

You can still run them on open vent, however i don't know why anyone would want to, it's a rubbish idea......Best thing to do with a 70's system is junk the lot and start from scratch. Benefits would include a much warmer house, and annual heating bills reduced by around 30%

I've managed to servive with a boiler and radiator valves and a pump why should I have stuff I've never needed.

Martin P

Alan Waddington 218/12/2018 18:56:15
390 forum posts
86 photos
Posted by martin perman on 18/12/2018 18:43:34:
I've managed to servive with a boiler and radiator valves and a pump why should I have stuff I've never needed.

Martin P

Yeah My Grandad managed perfectly well with a horse and cart until he got a truck........cheeky

The truth is, since we signed up to the Kyoto agreement, the focus has been on energy efficiency, so the government decides what criteria needs to be met when a new boiler is fitted. Therefore you or i don't have a choice in the matter.

blowlamp18/12/2018 19:10:15
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1133 forum posts
82 photos

I've got my Intergas installed along with weather compensation and an OpenTherm controller. I couldn't be happier with how it 'just works' throughout the seasons.

Come autumn, the system eases itself back on - barely noticeably at first, as radiators start to warm at very low levels, progressively increasing as the days & nights become cooler. The same happens in reverse as spring approaches.

It's very pleasing to be able to set the temperature and have the system maintain it despite changes in the weather. I'd definitely go with the same setup again if were were to move house or something.

Martin.

martin perman18/12/2018 19:50:08
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1404 forum posts
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Thats sorted then I shall get my two open fire chimneys swept and use the coal fires again. what happens when an oap's boiler fails and he cant afford a new one with all the stuff he supposedly needs.

Martin P

Samsaranda18/12/2018 20:41:21
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545 forum posts
4 photos

Martin, I don’t blame you wanting to shun modern technology,(condensing boilers); we had a condensing boiler fitted in the year 2000, it lasted 14 days before its first breakdown, a blown circuit board. Repaired under guarantee and over the next ten years it managed to eat a total of eight circuit boards, the boards cost about £170 each but because I was quite persistent in lobbying the manufacturer about their poor quality of components I managed to get all eight replaced fee of charge. Finally ditched that boiler and bought a new one which came with a seven year warranty, and to date this boiler has had extensive replacements which to date have all been free of charge. The end of the warranty is fast approaching so I will be looking for a suitable insurance to cover future eventualities. Modern technology is great when it works, as a standby we now have a log burner in the lounge so in the event of a boiler malfunction we can revert to basic technology to keep warm until the boiler is repaired. In fact we use the log burner all the time in winter and it circulates warm air throughout the house so our gas bill is now much reduced. My advice would be hang on to your old technology cast iron boiler as long as you can, they are certainly reliable.

Dave W

Alan Waddington 218/12/2018 21:06:29
390 forum posts
86 photos
Posted by Samsaranda on 18/12/2018 20:41:21:

Martin, I don’t blame you wanting to shun modern technology,(condensing boilers); we had a condensing boiler fitted in the year 2000, it lasted 14 days before its first breakdown, a blown circuit board. Repaired under guarantee and over the next ten years it managed to eat a total of eight circuit boards, the boards cost about £170 each but because I was quite persistent in lobbying the manufacturer about their poor quality of components I managed to get all eight replaced fee of charge.

Dave W

Ideal Isar by any chance ?

Samsaranda18/12/2018 21:14:45
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545 forum posts
4 photos

Ideal Icos 80.

Dave W

pgk pgk18/12/2018 21:48:30
1215 forum posts
278 photos

Getting off topic I know but woodburners and open fires sound cosy but if I didn't have my own woodland and unlimited timber I would avoid them like the plague. There's the nusiance/cost of PPE and chainsaws, then carting the stuff and cuttting and splittng again, storage in the barn and carting yet again indoors. The living room woodburner has a backboiler and gets through 3/4 of a small tractor loader bucket a day in winter, leads to dust and ash to be deal with as well as sweeping the darned thing every 3mths or so - a job i hate but saves £60 a time.

The only good thing to say is that woodsplitting with a maul paradoxically helps my back problems.

pgk

Alan Waddington 218/12/2018 22:06:51
390 forum posts
86 photos
Posted by Samsaranda on 18/12/2018 21:14:45:

Ideal Icos 80.

Dave W

Yeah, system version of the isar, same boiler different dress.....worst boilers ever made !

Good business for us repair men though cheeky

Trevor Crossman 118/12/2018 22:31:33
120 forum posts
13 photos

I don't do any fault finding with my combi, because when our old, inefficient, 16 years old one finally died,for just £24/month leasing fee we had a new boiler, all servicing,repairs and replacements included. It is now three years old and after 5 years I can purchase it for £1 and pay any future costs or start another leasing with a new boiler. No worries, no hassle, no capital outlay which I consider to be a good deal.

Trevor

Neil Wyatt19/12/2018 14:10:08
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Moderator
15223 forum posts
648 photos
72 articles

It's working!

Alan, if we meet up at a show, I owe you a pint!

Neil

Martin Kyte19/12/2018 14:30:26
1339 forum posts
9 photos

Can't you just bring the cows indoors during the winter.

Martin ;o)

J Hancock20/12/2018 13:21:40
249 forum posts

Forget troublesome 'Combis', save money and regress to the future with a simple 1980's design

Baxi Solo.

' Problem resolu ' , forever.

SillyOldDuffer20/12/2018 13:57:08
3621 forum posts
692 photos
Posted by pgk pgk on 18/12/2018 21:48:30:

Getting off topic I know but woodburners and open fires sound cosy but ...

pgk

The other problem is that they make the rest of the house colder! Central heating systems are thermally far more effective than open fires for two reasons:

  • In an open fire most of the heat goes up the chimney. The room is only warmed by radiant heat from the flame - the rest is pretty much wasted.
  • The fire burns warm air pulled from the room, wasting even more heat. Even worse, the warm air is replaced by cold air drawn from elsewhere in the building and ultimately from outside.  Brrrr.

In contrast a far smaller proportion of the heat goes up the chimney from a central heating boiler, and hot water is directed into the living spaces where the warmth is needed. Once it's got there, the waste due to air-flow is minimised and it's much less likely that cold air will be pulled inside.

An open fire is a pump for replacing warm air with cold. The pumping effect is so strong that coal mines were once commonly ventilated by furnaces. Though it looks charming and is simple, burning wood or coal in a hearth is a poo heating system.

Dave

Edited By SillyOldDuffer on 20/12/2018 13:58:50

Pete White20/12/2018 13:57:12
28 forum posts
3 photos
Posted by pgk pgk on 18/12/2018 21:48:30:

as well as sweeping the darned thing every 3mths or so - a job i hate but saves £60 a time.

And there lies another grip for us oldies. Insurance companies are getting difficult about paying out on chimney fires and are starting to request the "Sweeping Certificate", which a member to the ""Chimney Sweep Club" gives you,after you give him your hard earned £60............................

Used to give our man £20 and we were both happy..............mind you not sure he was properly trained, only 40 years experiance ...............

Martin King 220/12/2018 14:03:42
545 forum posts
176 photos

Having just gone through a nightmare with a leak fault on our Glow Worm Ulracom 30cxi Combi boiler I am now having lots of grief with radiators that will not turn down on the TRV.

The boiler was leaking through the pressure relief valve, about a bucket or so every 2 days.

Heating Engineer changed the valve and checked the expansion vessel to see if it was holding pressure, all OK. Next we were not getting any decent hot water pressure or temperature. Plumber comes back and fits a new plate exchanger that I sourced on EBay (genuine part), did a power flush of the whole system which had very little muck in it, almost clear water, cleaned the Magnetic reservoir also.

Still getting the relief valve leak and finally tracked it down to one of the filling loop valves which was passing water. Fitted new valve and leak is cured now.

Strange as we never use these as we have an separate filling loop?

Refilled the system after adding Fernox, bled all the rads starting at the top and pressurised the system to 1.5 Bar cold.

Hot water pressure and temperature now good and heating mostly works with the new Hive thermostat I fitted.

I have removed the TRV and shut off the small radiator which is near the Thermostat to avoid fals readings.

EXCEPT we have two radiators (large doubles) one downstairs in lounge and one in our upstairs bedroom which do not seem to respond to the TRV settings just stay full on whatever we do?

I have removed the TRV heads and checked the pins for movement and tapped the side gently with a hammer and they seem free not stuck.

Have tried swapping each valve for the one from the hall but makes no difference?

Now out of ideas! ???

Any help welcome please!

Martin

martin perman20/12/2018 15:37:11
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1404 forum posts
60 photos
Posted by SillyOldDuffer on 20/12/2018 13:57:08:
Posted by pgk pgk on 18/12/2018 21:48:30:

Getting off topic I know but woodburners and open fires sound cosy but ...

pgk

The other problem is that they make the rest of the house colder! Central heating systems are thermally far more effective than open fires for two reasons:

  • In an open fire most of the heat goes up the chimney. The room is only warmed by radiant heat from the flame - the rest is pretty much wasted.
  • The fire burns warm air pulled from the room, wasting even more heat. Even worse, the warm air is replaced by cold air drawn from elsewhere in the building and ultimately from outside. Brrrr.

In contrast a far smaller proportion of the heat goes up the chimney from a central heating boiler, and hot water is directed into the living spaces where the warmth is needed. Once it's got there, the waste due to air-flow is minimised and it's much less likely that cold air will be pulled inside.

An open fire is a pump for replacing warm air with cold. The pumping effect is so strong that coal mines were once commonly ventilated by furnaces. Though it looks charming and is simple, burning wood or coal in a hearth is a poo heating system.

Dave

Edited By SillyOldDuffer on 20/12/2018 13:58:50

Whilst I dont disbelieve what you have said could you explain why when we used to have a coal fire lit in the front room we had to turn the central heating off because it was so damn hot in the house and our bedroom was always toasty from the heat from the chimney breast which was above the room with the fire in. The house has cavity wall insulation, 300 mm of loft insulation and double glazed through out.

Martin P

Martin P

blowlamp20/12/2018 16:21:39
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1133 forum posts
82 photos
Posted by Martin King 2 on 20/12/2018 14:03:42:

Having just gone through a nightmare with a leak fault on our Glow Worm Ulracom 30cxi Combi boiler I am now having lots of grief with radiators that will not turn down on the TRV.

The boiler was leaking through the pressure relief valve, about a bucket or so every 2 days.

Heating Engineer changed the valve and checked the expansion vessel to see if it was holding pressure, all OK. Next we were not getting any decent hot water pressure or temperature. Plumber comes back and fits a new plate exchanger that I sourced on EBay (genuine part), did a power flush of the whole system which had very little muck in it, almost clear water, cleaned the Magnetic reservoir also.

Still getting the relief valve leak and finally tracked it down to one of the filling loop valves which was passing water. Fitted new valve and leak is cured now.

Strange as we never use these as we have an separate filling loop?

Refilled the system after adding Fernox, bled all the rads starting at the top and pressurised the system to 1.5 Bar cold.

Hot water pressure and temperature now good and heating mostly works with the new Hive thermostat I fitted.

I have removed the TRV and shut off the small radiator which is near the Thermostat to avoid fals readings.

EXCEPT we have two radiators (large doubles) one downstairs in lounge and one in our upstairs bedroom which do not seem to respond to the TRV settings just stay full on whatever we do?

I have removed the TRV heads and checked the pins for movement and tapped the side gently with a hammer and they seem free not stuck.

Have tried swapping each valve for the one from the hall but makes no difference?

Now out of ideas! ???

Any help welcome please!

Martin

Make sure the radiators are balanced via the lockshield valves.

A starting point from fully closed is about 1/4 - 1/2 a turn open.

Martin.

Martin King 220/12/2018 17:05:20
545 forum posts
176 photos

Blowlamp, many thanks, trying that now.

Martin

Samsaranda20/12/2018 17:55:46
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545 forum posts
4 photos

Martin P, we get the same effect from our inset woodburner stove, the rest of the house is heated through with warm air that circulates and the room above the woodburner has a lovely warm chimney breast running through it, our cats didn’t take long to suss that out. Ours is only a small woodburner but the heat output is phenomenal, we get both radiated and convected heat from it in the lounge, I think Dave’s comments relate only to an open grate fire, modern enclosed wood burners are highly efficient in comparison, very happy with our woodburner.

Dave W

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