Advice required on 10 year old central heating system..

Hello,

I am looking for a little bit of advice on my central heating system. I have just bought a small 2 bedroom terraced house and have been given a bit of doom and gloom by British Gas (I know maybe not the most popular people on here but I am a total novice when it comes to central heating and hot water supplies as this is my first house.

The system is approximately 10 years old running off an Ideal Elan NF230 boiler supplying a Thermal Storage Cylinder (set at 75c). It's got a small copper header/expansion tank above the cylinder with a copper lid, 2 pumps, and a Room Thermostat/programmer in the lounge.

I have done a bit of digging around on these and if I understand it correctly, the boiler heats the water in cylinder which is used to feed the radiators, the 2 pumps are connected one to the boiler feed and one to the radiator feed. The HW is then fed at mains pressure through a heat exchanger/coil inside the tank to heat and passed to the outlets.

The central heating system is all non-barrier plastic pipe and of course is original with the house except for pipe work around the cylinder which appears to be copper, according to the British Gas engineer the plastic pipe (and a few pages I have looked at on the internet) is a very bad thing[tm].

He basically said that the system is a poor design, with a low powered boiler (which is probably fair point, the maximum flow seems to be 80c where as the tank wants to be 75c so there is not much redundancy there). So its running at full kilt. He said the plastic pipe will allow lots of oxygen in the system to corrode the radiators (I have had

2 off with the help of my dad and they were full of black cr*p but none seem to be holed).

He said what I will find is that my HW is not great when the heating is running because the water from the cylinder is being cycled to the rads which makes sense. I have not moved in yet, as I am decorating the place first. He also said its very prone to limescale (we do live in a hard water area).

They did agree to look after my boiler and system on HomeCare 200 but obviously had a good winge about how poor the system is and that I should think about a PowerFlush (which I can ill afford to be quite honest). He admitted I was getting circulation in the CH and so there was no blockage, and it should be working so agreed to cover it. He even went to far as to say that he would not have bought the house purely because of the central heating :O I was a bit taken aback by that, surely its not that bad?

So without changing the whole system, pipework etc etc I am planing to do the following;

Drain the system fully down and flush out the radiators as much as I can by running water through them. They all heat up well except the big rad in the lounge which has a cold spot at the bottom (which I suspect is full of crap).

Then use Purimachos Flushex to see if I can clean the system further, before adding some Purimachos Protex Inhibitor to a fresh filled system.

What do people think? Should I really think about replacing the system if it's working? As I have said I have not moved in yet so not spending a lot of time there so the system is on low. I suppose until I move in I wont see how good the CH and HW supply is although I suspect as a single bloke living there alone its going to be adequate.

Thanks very much for everyone's time, patience and any advice. (Thanks also to Ed Sirett for pointing me to here and his response)

Mike

Reply to
Mike
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I think things may not be anywhere near as bad a BG are suggesting. What is the current boiler power? Around 10kW or 35 kBtu/hr should be fine.

Reply to
Ed Sirett

I thought most boilers (bad name I know) tended to max out at around 80c or so - or at least, their thermostat turns the burner off at that point. Do boilers really go above that temp?

D
Reply to
David Hearn

I really think you're better off to move in and see what happens bu

Power Flushing is really terribly straightforward - and there i absolutely no need to pay the £650 +VAT that BG want for doing it. I hired a Power flush pump and chemicals(bought those!!) for the gran sum of £95 and followed the very detailed instructions to the letter. Took me 3 hours and it has given my CH and HW a new lease fo life. B had told me that the boiler was irrepairable and could not stop i "kettling". Now it's a smooth and quiet as new and although it won last forever (its 18 years old) I have bought time to work out what t do when im ready to replace it. I hired my unit from Kamco in S Albans, herts - sure there is soemwhere near you that can do the sam

-- alexbartman

Reply to
alexbartman

My boiler is actually older than yours and was also kettling quite badly. I used the Screwfix offering for cleaning the system, left it in there for the maximum 5weeks and then injected the Fernox treatment once that was washed out.

The system has been as quiet as a mouse this winter and I expect to get a few more years out of it yet. Many of these so called engineers are no more than salesmen or more acurately, conmen.

Andy

Reply to
Andy Cap

Yes if the only thermostat fails. Otherwise it depends. A sophisticated modern boiler that is in calibration might go to 82 flat out with an option for 87 (useful if the radiators are undersized).

Reply to
Ed Sirett

Hi,

Thanks all for the replies, the boiler is only 8.8kw and 30,000 BTU/H if that changes things?

Incidently, my boiler does kettle a bit but isnt too bad, we will see if the flush and treatment helps.

I have noticed a few of the radiator valves are weaping a bit so I need to look at that too.

I will try the screwfix route for flush and treat before going the whole hog on hiring the kit to do a DIY powerflush I think.

Is it ok to replace the radiator valves? My dad is pretty confident we can do it easily enough and I want to put two TRVs on the bedroom radiators if I can anyway. So while I am draining the whole system it may be just as well to replace the weapy valves.

Is there anything I need to know about TRVs, Valves with respect to my

10mm plastic pipe or should they (screwfix, toolstation ones) be ok to fit?

My dad has fitted my TRVs on 10mm metal pipe but he is little unsure of the plastic type.

Thanks again,

Mike

Reply to
Mike

Since you cant spot a con, I suggest staying away from salesmen altogether. And I'd cancel the BG maintenance contract if you've still got time.

NT

Reply to
meow2222

Yes, they are very cheap. But if they are otherwise in good condition it may be sufficient to just tighten the gland nut .

You need to be aware of "balancing". If it has already been done (unlikely!!) the lockshield valves will be set in the correct position so note the settings so you can reset them after replacing the rads. Balancing is explained here

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My dad has fitted my TRVs on 10mm metal pipe but he is little unsure of

Plastic and copper pipe is inter-operable so should fit the same if you have 10mm TRVs. They are more commonly available as 15mm though which you could use with a 15/10mm reducer.

Phil The uk.d-i-y FAQ is at

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Reply to
Phil Addison

Thanks for that Phil.

One final bit of info, will I need to cut the plastic pipe to fit the new olive and nut on for the compression fitting into the TRV/Radiator Valve? I believe the pipe is HEP20.

If I do have to cut I may need extra pipe for the downstairs rads. They have elbows at 90 degrees to allow the pipe to go into the walls. The upstairs have extra length which I can pull through the floor, they go directly down.

Looking around on the net, it appears 50m is the smallest length of

10mm pipe I can get, clearly I need less than a metre. Any idea where I can find or aquire "cut offs"?

Also are the Sentinel X400 and X100 products ok for use with plastic piped systems?

Cheers for the help.

Mike

Reply to
Mike

Thanks for that Phil.

One final bit of info, will I need to cut the plastic pipe to fit the new olive and nut on for the compression fitting into the TRV/Radiator Valve? I believe the pipe is HEP20.

If I do have to cut I may need extra pipe for the downstairs rads. They have elbows at 90 degrees to allow the pipe to go into the walls. The upstairs have extra length which I can pull through the floor, they go directly down.

Looking around on the net, it appears 50m is the smallest length of

10mm pipe I can get, clearly I need less than a metre. Any idea where I can find or aquire "cut offs"?

Also are the Sentinel X400 and X100 products ok for use with plastic piped systems?

Cheers for the help.

Mike

Reply to
Mike Myers

Thanks for that Phil.

One final bit of info, will I need to cut the plastic pipe to fit the new olive and nut on for the compression fitting into the TRV/Radiator Valve? I believe the pipe is HEP20.

If I do have to cut I may need extra pipe for the downstairs rads. They have elbows at 90 degrees to allow the pipe to go into the walls. The upstairs have extra length which I can pull through the floor, they go directly down.

Looking around on the net, it appears 50m is the smallest length of

10mm pipe I can get, clearly I need less than a metre. Any idea where I can find or aquire "cut offs"?

Also are the Sentinel X400 and X100 products ok for use with plastic piped systems?

Cheers for the help.

Mike

Reply to
Mike Myers

Thanks for that Phil.

One final bit of info, will I need to cut the plastic pipe to fit the new olive and nut on for the compression fitting into the TRV/Radiator Valve? I believe the pipe is HEP20.

If I do have to cut I may need extra pipe for the downstairs rads. They have elbows at 90 degrees to allow the pipe to go into the walls. The upstairs have extra length which I can pull through the floor, they go directly down.

Looking around on the net, it appears 50m is the smallest length of

10mm pipe I can get, clearly I need less than a metre. Any idea where I can find or aquire "cut offs"?

Also are the Sentinel X400 and X100 products ok for use with plastic piped systems?

Cheers for the help.

Mike

Reply to
Mike Myers

Why would you want to cut it, unless it is damaged? It must me in good condition, and you must use the special stainless steel inserts in the cut end to support the pipe wall at the fitting end. Actually I'm not sure if that is true for 10mm, but it certainly is for 15mm - check on the Hep20 website

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read up on the instructions. It is easy to use, but important to cut it cleanly with the special knife (£4-£5 for a generic one) and to make sure the pipe is inserted the full depth in the fittings. The Hep pipe has marks on it to facilitate that. And I repeat, don't forget to use the steel inserts in each cut end.

15mm is sold in 3m straight lengths. 10mm might be too. If you can't get a short length just use a length of copper instead. It is totally compatible so you could come out of the TRV in 10mm copper (or 15 for that matter - may be a cheaper TRV?) and use a plastic or compression coupler to connect to your existing pipe work. Actually it is preferable to use copper where it is visible anyway, as plastic never runs in a true straight line and sags slightly when hot.

Yes. But check the Hep site.

Phil The uk.d-i-y FAQ is at

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Reply to
Phil Addison

radiator valves which are terminated into HEP20 and replacing them for new valves, 2 of which will be TRVs. (the old valves are weeping and look cruddy).

If I remove the existing pipe, will it be ok to terminate to the new valves, or will I have to cut the existing end which has the compression olive and fit new?

I am assuming the pipe will already have the stainless steel inserts, and the old olive (wont that be damaged due to the compression fit?).

I had assumed I fit new inserts and new olive from the new valve then remake the compression joint. I has assumed this is why I would have to cut the end of the pipe.

Thanks and sorry for my silly questions but I am a novice with this, and my dad who has done his own copper work doesn't know about plastic.

Mike

Reply to
Mike Myers

They are usually ok to re-use so long as it hasn't been over-tightened. Check it has not cut too deeply into the pipe if re-using it.

You don't get inserts with valves. They come from the plastic pipe supplier.

The compression nut will normally be trapped on the pipe by the olive. You then have two options. Use the existing trapped compression nut to attach the pipe to the new valve (clean up the threads first if caked up), or cut the pipe back to a clean portion and use a new insert (ideally, but you can get away with re-using the same one) and your new fittings. You may need to extend the pipe with copper as I mentioned before. Use a very light smear of Boss White on the olive (not the threads) and before reassembling. The Boss White is for lubricating the joint during tightening as much as it is for sealing. Don't use Boss White on any plastic fittings, should you have any.

Not a silly question at all - we all started at the beginning. I bet it won't be long before you are answering questions here.

Phil The uk.d-i-y FAQ is at

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Reply to
Phil Addison

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