CH temper mental

[Mr. Tickle]

Yeah, this is where i'm getting lost. I have a basic understanding of thermodynamics and laws of conservation, which is why i don't see the problem!

WHen i say the boiler is on, i mean that the fan thingy turns on, it makes a bit of a racket, you can hear what appears to be a piezo clicking, then it 'fires up'. I am looking through an 8mm hole in the front of the boiler and there is a blue flame - if i look hard enough i'm sure I can see a 'run' of these flames.

Near the valve, when we are having this problem, NONE of the pipes are hot AT ALL. they are all just warm.

The pipes coming from the boiler (literally on top of the boiler, coming out of the case) are just warm also.

I am nearly 100% sure the pump is running. I can turn it down to 1, then up to 2 and 3 and there is a disctint noise of gushing water. I can also feel slight vibration within the pipes themselves, which goes when the pump stops. This tells me that the pump is running round ok but i could be wrong.

I was told that the boiler won't fire unless the pump is running as a safety feature - but I don't see how the boiler can be on with the pump - and there be no hot water anywhere in the system.

Again guys, I beleive there is water pumping round.

I have measured the temp of the water in the tank and when the CH stops working as it should, it is the heat from the tank being pumped round the CH - it gets cooler as the rads take the heat from the tank.

I can only see a bit of a flame - i presume then that the boiler can 'fire up', have a flame inside it, but not actually be on?

There doesn't seem to be any difference in the boiler when it is working okay and when it isn't - the same sort of flame is visible.

When it's not working, neither pipes from the boiler are hot. My feeling is that if the pump wasn't working, the boiler would heat up water and it would rise - pump or no pump - up one of those pipes, making at least one of them too hot to touch (because the rads can get that hot when they are working). But then I can see the evidence as above that the pump IS running.

Surely if a voltage is sent to the boiler, it starts up and there's a flame inside - with all associated noises - it is going?

HELP!

 

[Mr. Tickle]

Does anyone know the telephone number for Gloworm? I'd like to give them a call.

Cheers,

Mr. Tickle.

 

[Mr. Tickle]

I've just come in from work and the rads are cold.

The progs calling for CH, the therm is calling for CH but no action. The valve was in Mid position. I pulled it over to MAN and the twiddled with the speed setting on the pump and it has started the boiler.

This is not what usually happens. This happens sometimes and is almost always followed by the original problem where it will heat up and then cool down after about an hour.

I will see what happens tonight.

Is this a sticky valve? It still doesn't explain the rest of the problem, however.

Thanks for any advice you may have. I tried to call Gloworm but the only number I can get it an 09 number and I really don't want to pay them so i can explain. I don't have faith that they will be able to tell me whats wrong.

I spoke to another heating engineer yesterday who couldn't figure out what was wrong but said he'd talk to someone else and the Gloworm rep and get back to me.

Thanks again,

Mr. Tickle.

 

[Mr. Tickle]

After I pulled the lever, the water started pumping round and the boiler fired up. The rads got pretty hot but now I've just noticed the rads getting cold again. Everything is switched on, calling for heat and appears to be running.

Can someone suggest a test I could try to get some heat out of it? I have yet to get to the meter to see how much gas is being used - is this the next best thing to try?

I've now cranked up the tank therm and put HW on the programmer ON, the valve has moved to mid position and the boiler is still firing, however, i know from the above that this does not work.

Thank you,

Mr. T.

 

[felix]

Since you can't really see the flames in the boiler, watching the meter is your best bet. I'm quite sure you'll find only a pathetic amount of gas is being used.

I also think you're spot on about heat from the cylinder going to the radiators, though that in itself means that the pipe runs are all wrong. It all makes sense. The cylinder heats up slowly over a long period then, when you ask for CH, you get a burst of stored heat - but not for long.

The cure may not be so simple. You must have a blockage in the gas flow somewhere. I can't see it being upstream of the gas valve because the pilot light would (almost) go out when the boiler fired and then the flame failure device would shut everything down. It must be in the gas valve itself or, if you're really lucky, in the burner jet.

If you remember bunsen burners from your school chemistry lab you'll know what I mean by the burner jet. The burner bars themselves should be removeable. The jet will be a lot bigger than any bunsen and you should be able to clear a blockage without breaking into any gas tight joints. Unfortunately, it's much more likely to be gas valve trouble.

 

[Mr. Tickle]

Hi everyone -

Just come in from work - rads are cold again. The therms etc. are all open. I have moved the valve over manually to MAN and the boiler/pump started up.

I have looked at the Gas meter, but I'm not sure I'm reading it right.

It says:

2846 5

the 5 is in red and to the right of that, there is an analogue clock type meter going round. I watched this go round 4 times, but the other numbers don't change. Am i right in thinking that this seperate counter is .01 of a ft/3? (with the Red 5 being 0.1?) So it's got to go round 10 times before the Red 5 at the end will change?

The small clock type meter goes round 180 degrees in one 60 second period. Which, if the above bit is right, is like, 0.005 ft3/minute.

Thank you again for your continued support.

Mr. Tickle.

 

[Mr. Tickle]

The rads have cooled again and the boiler was off aswell - even though everything said go. I put the water on and turned the CH off and the water is getting damn hot. I think the boiler problem may be intermittent to say the least.

I am going to leave it on HW for a while - it doesn't seem to be going round the CH pipework. I have turned the therm on the tank up to 70 from 60 to see how hot it will get the tank.

I'm going to read the meter again, see what it's doing when i know things are getting hot.

Then i will throw the HW off and put the CH on and see what happens. I'll put the CH on first so the boiler stays on.

Then read the meter again.

Let you know what happens!!!

Mr. T

 

[Mr. Tickle]

OK, so the boiler is 'going' and the water is getting hot - 70oC. The gas meter was turning at the same rate as it was before, maybe a little slower if anything! Maybe that proves the boiler is firing up? Would the pilot light be able to heat the water in the tank to that sort of temperature? We usually have HW on for 1 hour in the afternoon 4-5 and one in the morning 4-5. We don't notice a problem with water temps but perhaps the pilot was doing that? Possible?

I've turned HW off and CH on and the valve has moved over and is pumping pretty damn hot water around the CH. I will keep my eye on it.

It's weird 'cause sometimes it displays a pattern and then it will just go away and work all the time.

Cheers,

Mr. T.

 

[felix]

Hell will freeze over before the pilot light can make a noticable difference to your water tank.

On a typical gas meter that last dial measures cubic feet but check the small print on the meter to be sure. If yours is typical then your boiler is using 30 cubic feet per hour. That's 9kW in new money which is smaller than the average boiler but still a decent amount.

You do seem to have an intermittent problem but the common factor, as I perceive it, is that you only have the problem when you aren't asking for HW. In this condition the boiler's gas valve is powered through a microswitch inside the three port valve. Perhaps the voltage is low and the valve isn't opening properly.

My next test would be to set the controls to CH only and see how fast the meter moves.

 

[ChrisR]

Has your neighbour been improving his house recently - have you heard any unfamilliar noises from beneath the floor? That heat has to be going somewhere.

Some prosaic solution will probably be found, but, where are you Mr T? I feel the urge to publish a Paper on your heating system, as it clearly defies the known laws of thermodynamics and I might win a prize.

 

[PEDANTICVINDICTIVEMAN]

50p a minute and corgi number required to talk to Glowworm rip off line

 

[Mr. Tickle]

I am in the west Midlands. Near Dudley.

Can someone confirm for me that I am reading the meter right?

There are 4 white numbers on an analogue dial - not the clock face type, but the miliage-in-a-car type.

Then there is on of these numbers in RED.

To the left of this, there is a red 0, or square with rounded corners that I think looks like a 0. Then there is a clock face dial.

On the meter is says ft3 but it doesn't say where the decimal point is.

The meter is made by schlumberger.

I can take a pic if it helps.

I can now add another heating engineer to the list that cannot find a problem.

Everyone comes in, turns it on, feels the rads getting hot then they leave saying 'but it works'. Only for it to go cold again in an hour.

I checked the gas reading last night with the rads bouncing off the walls and it was using about 0.1ft3/min. If I have the meter reading correct.

Is the very last number on the meter cubic feet, and the others are tens, hundreds, thous - of?

Thanks for your help.

If anyone can suggest a good heating engineer that would be great. I am at the end of my tether now and really just need reliable heating.

It has worked fine all over the weekend, but I don't want to crawl back under my duvet just yet!

Thanks,

Mr. Tickle.

 

[Mr. Tickle]

I can ask for HW + CH and still have this problem, so it's not like I'm only getting this only when I'm not asking for HW.

HELP!!!!

 

[Mr. Tickle]

ChrisR -

Not that I know of! I can trace our gas line from the meter to the boiler and there's no dodgy branching or garden hose+ducktape arrangement that I can see.

I know this sounds stupid and that it shouldn't be working like this, but i'm sure that i'm missing something that would be picked up. I guess I'd like to think that but we've had several 'professionals' in and non of them have a clue what is going on.

Cheers,

Mr. Tickle.

 

[felix]

You're reading the meter wrong. There is no decimal point and that little clock goes round once per cubic foot. This means you're using a whole cubic foot per minute. That's nearly 60,000 btu per hour or 18kW which is about right for the average domestic boiler.

The next thing you need to do is to watch the meter when the boiler appears to be on but there isn't much heat coming out.