New World CH502 boiler pilot light problem

[JDDP]

The pilot light on my New World CH502 boiler has gone out and refuses to re-light, properly. I've had the thermocouple replaced by a gas engineer, but this hasn't fixed it. I've read all the the comments in response to Actrosman's plea from a while ago from Agile, swbjackson, namsag, gaswizard, and corgibloke and it maybe that the gas valve (ITT Maclaren 24v) is at fault. I know my CH502 is nearly 40 years OLD, but I don't want to replace it as the aforementioned gas engineer says that the 15mm gas feed would have to be replaced with a 22mm pipe, which would mean ripping my house apart. I'd be very happy to replace all the controls on the CH502 rather than wreck my house !

CAN ANYONE HELP ?

 

[45yearsagasman]

If indeed it is the gas valve then you'll only get a used one. Try eBay.

I've just seen one on there for £299

 

[JDDP]

I'm not sure if it is the valve - I'm Zeroyearsagas man - It looks a fairly simple piece of equipment. I open the control panel cover, and inside there are are two rectangular boxes. The top one I have identified as the ITT maclaren valve, then below that is box with a green cover that houses what I would call the 'volume control' (it has a big T , and Teddinton printed on it). Also at the top left hand corner there is a circular disc with two wiring terminals on it, & a v. small blue button in the centre.

I'd be happy to replace the lot to get it running again. It has been a splendid piece of kit. I don't know what the 'official' names other components, but maybe, as you have 45 years experience of gas equipment, you'd know and also have an idea of what the problem is. I would be very pleased to receive your advice. Thanks for your help. JDDP.

 

[45yearsagasman]

The box below is the modulating thermostat and would not be the cause of your problem. It would be necessary to measure the thermocouple circuit to determine the cause. I would suggest getting another check done on the thermocouple and valve. It is too difficult to explain step by step how to do it.
Good luck with your boiler, but the time to replace it is, I suggest, fast approaching.

 

[ianmcd]

you would probably only need to upgrade the gas pipe to 22mm if you were putting a combi in, if your heat only boiler has run all this time on 15mm then just replace it with another heat only or system boiler and the 15mm will be fine, wont last as long as the old fella though

 

[Agile]

As I always say this is a very efficient boiler ( apart from the permanent pilot light ) and there is no reason to replace it if it can be repaired. Even if a repair was to cost £384 then its still cheaper than a new boiler.

I don't expect that it is the gas valve anyway! Its a very simple boiler but I don't remember repairing any during the last 10 years!

I still have two of these in use and a third for spares ( installed ) in my own loft ( although its no longer in use ).

We are not permitted to give you DIY advice on this forum!

But anyone who is to diagnose the fault will need to use an electronic multimeter!

Tony

 

[JDDP]

Hello 45yearsagasman and Ianmcd. Thanks for your replies.
What happens is this. I press (hard) the rotary control knob at the position marked 'pilot' and hold it down. Then I press the button that produces the spark, which ignites the pilot. I continue to press the rotary control down for a minute or two, and looking through the little window I can see the blue pilot flame. THEN having held the rotary knob down for a while, I then start to turn it to the 'on' position. The blue flame stays lit, but when the knob is almost at the end of its journey to the 'on' position.....the little swine gets tired and goes out.

As the rotary control is directly connected to the gas valve and I have had the thermocouple replaced (by a Gas Safe registered engineer), this leads me to think that the gas valve is 'kaput'. Do you think that this is a reasonable deduction.

 

[Agile]

We know exactly what happens.

What we don't know is why. The only way to know that is to be there to test it with a meter.

Your deduction is probably not correct!

We don't give gas related DIY advice here. You need a competent gas reg. engineer who knows how to diagnose faults rather than just change parts.

Did your fellow even use a meter before replacing the thermocouple? No, he did not! He is just a parts changer!

Tony

 

[JDDP]

Hello Agile. You are absolutely right about the boiler. It has been absolutely great since I first had it installed in 1977 (I did all the plumbing, but left the bit with explosive potential to the professionals). I would be extremely happy to pay £384.00 to have this old friend working again. As you rightly say it is a very simple boiler and as you have a lot of experience with these, what do you think it may be. I really don't want to have to throw it away. THANKS.

 

[Agile]

I have not visited you but would say that whilst it could be the gas valve it probably is not.

But we don't give gas related advice here.

You need a capable engineer who can diagnose faults. Probably well less than 10% of the gas registered engineers.

Also I don't approve of anyone who changes parts which don't fix the problem and then has to cheek to charge you for his incompetence!

Your boiler is totally repairable although that might mean using second hand parts and I would be disappointed if you don't gat it fixed. As you say they are great little boilers. Actually based on an Ascot instant water heater!

Tony

 

[ianmcd]

is this the same one that you need ?

http://www.ebay.co.uk/itm/Gas-Valve...arden_Hearing_Cooling_Air&hash=item461b2b14b2

 

[JDDP]

Hello again Agile.

I'm not looking for DIY advice.
I just want to understand the problem.

Maybe the Gas Reg. engineer, who changed the thermocouple, is just aparts changer, but as this super appliance is so old its ancient style is very unfamiliar to these modern blokes ! He did say, when he first saw it 'Wow ! I've never seen one of those before

What I probabaly need is a chap who is almost as old as me, (do you know any) !

 

[Agile]

Any competent diagnostic engineer would be easily able to diagnose the fault on yours!

You seem to think that I can tell you what is wrong without testing on your boiler. It needs someone if front of your boiler.

The only part of your boiler which is rare to find is the non electric modulating element. I can only think of one other boiler with that. But its irrelevant as that is not at fault.

Tony

 

[JDDP]

Hello Ian.

I think it is the same beast as fitted in the New World boiler. It certainly looks the same from the outside. The connections are all in the same place. I'd have to be 100% sure that it was the correct part. Thank you.

 

[ianmcd]

if the one you have is blue control knob then this will fit