Boiler Overheating Very Hot!! - Central Heating System HELP!

[Agile]

A very large number of local firms are still registered with CORGI and I used to get quite a few jobs through them although I think thats reducing now.

Tony

 

[moviemakernow]

Hi Again,
Thank you very very much for your reply, I 'am in Cheshire. This job was done 4 week's ago, I complained on the second day before they finished at noon, that the new rads were not hot, two days later the boiler got very very hot, the pressure dropped to one digit off zero and the copper pipe outside must have let off steam or water and the bricks were saturated beneath it.

As the engineers would not return, I called out worcester on a one call out fee, the engineer said it had overheated, the wall was black at the side and also the ceiling above it, he checked the flue as it is an open flue and then carried out his investigative tests. He opened a valve on the top of the boiler and a tremendous amount of air started to come out for a very very long time. He did say that wasn't right and it shouldn't do that for that length of time. The diagnosis on that day was a fault on the system, probably sludge in the pipes and it would benefit from being flushed out with x400? or something similar, this was only a recommendation and he would not put it in writing.

As a gesture of good will, he replaced the pcb board.

Well from what you describe it's clear these chaps were cowboys! They failed to purge the air from the boiler and system before re starting it. Air trapped in the boiler will have caused the heat exchanger to over heat! It will probable have caused permanent damage to the heat exchanger as it is designed to work with water in it not air!! You need to get it checked out properly never take the risk of using a faulty boiler.

 

[igiveitup]

The engineer that fitted the new rads, (seven in total) with two additional rads added to the system, is a gas safe, corgi registered Heating Engineer and Plumber.

Have you see his Registration Card?

If not, have you checked his registration at Gassafe Register?

Corgi registration means nothing now.

Thank you very much, I have checked the gas safe register from your link and this person only has a four digit gas safe registeration number, the rest appear to have six digit numbers, with a couple having five digit numbers.

Does it depend on how long one has been registered, as to how many numbers in the registeration? or is it something one pays for and renews each year? Sorry to trouble you further.

 

[Agile]

We pay each year and have a registration number which was allocated when we were first registered. My first one was 68,xxx. Now the numbers are over 500,000.

Its theoretically possible for him to have a very early one but you might need to add leading zeros into your Gas Safe search.

If is is registered he will be on the G-S site alternatively you can call them on 0800 408 5500.

Tony

 

[tamz]

I've got a 4 digit gas safe number but then again i'm an old cant

Have you see his Registration Card?

When did that become a legal requirement to fit some radiators? or are you advocating it should be?

 

[igiveitup]

The engineer that fitted the new rads, (seven in total) with two additional rads added to the system, is a gas safe, corgi registered Heating Engineer and Plumber.

Have you see his Registration Card? No I haven't seen his registeration card.

If not, have you checked his registration at Gassafe Register?

Corgi registration means nothing now.

Thank you very much, I have checked the gas safe register from your link and this person only has a four digit gas safe registeration number, the rest appear to have six digit numbers, with a couple having five digit numbers.

Does it depend on how long one has been registered, as to how many numbers in the registeration? or is it something one pays for and renews each year? Sorry to trouble you further.

 

[igiveitup]

The engineer that fitted the new rads, (seven in total) with two additional rads added to the system, is a gas safe, corgi registered Heating Engineer and Plumber.

Have you see his Registration Card? No I haven't seen his registeration card.

If not, have you checked his registration at Gassafe Register?

Corgi registration means nothing now.

Thank you very much, I have checked the gas safe register from your link and this person only has a four digit gas safe registeration number, the rest appear to have six digit numbers, with a couple having five digit numbers.

Does it depend on how long one has been registered, as to how many numbers in the registeration? or is it something one pays for and renews each year? Sorry to trouble you further.

HELP!! Can anyone advise and confirm if 22mm copper pipe is compulsary to use for the flow and return from a combi boiler for the heating system, would be grateful for any help regarding this please

 

[misterdubya]

This is not to due with the same fault you had in March / April is it?

Mr. W.

 

[Axel]

This sounds like an issue to be dealt with by Trading Standards.

 

[tamz]

1st metre off the boiler should be copper.

 

[igiveitup]

1st metre off the boiler should be copper.

Is it ok to use 22mm for the first metre and then reduce down to 15mm all in copper pipe?

Does the measure of 15mm for carrying 18,000 btu's 22mm for carrying 55,000 btu's and 1inch for carrying 100,000 btu's. Is this right?
If the radiators downstairs total approx 38,000 btu's and the combi boiler is upstairs, should the flow and return be in 22mm pipe?
If it has been reduced down to 15mm after the first metre, would this affect the heating as regards the radiators being robbed of heat?

Any advice most welcome.

 

[igiveitup]

If a combi boiler is fitted upstairs and the flow and return from boiler are in 22mm for the first metre, reducing down to 15mm would it affect the heating of the rads downstairs?

Is the measure of 15mm to carry 18,000 btu's 22mm to carry 55,000 btus and 1inch to carry 100,000 btu's correct?

If the flow and return are in 15mm and the rads total approx 38,000 btu's downstairs will it rob the rads of heat.
Would balancing help?

OR would the pipe have to be changed to 22mm to solve the problems.
Also would the 15mm pipe affect the flow of hot water i.e. Take longer to fill a bath for instance?

Would appreciate help and advice on this matter please

 

[spraggo]

Is the measure of 15mm to carry 18,000 btu's 22mm to carry 55,000 btus and 1inch to carry 100,000 btu's correct?



It would be interesting to know how you arrived at these figures, as it seems they are calculated per 100ft of pipe, If the pipes are shorter they will more.

 

[tamz]

The outputs shown are an old rule of thumb which was (still is) used and is reliable for std systems where guys fitting them do not have the time to sit down and work things out.

A 15mm pipe will carry around 10kw at a velocity of 1.5m/s and temperature drop of 11 deg
Change the velocity or the temp drop and the capacity changes.
1.5m/s with 20 deg drop = 18kw
0.3m/s with 11 deg drop = 2kw

The output (carrying capacity) through a pipe of a given size is related to the resistance through the pipe and fittings and the velocity at which the water travels.
Greater velocity = more capacity + more noise.
Greater temperature drop (water moving slower)= more capacity

Higher outputs can be obtained by increasing the velocity (pump speed) which moves more mass and overcomes more resistance but produces more noise. Ideally you don't want the water moving above 1.5m/s

Bit simplified answer.... put in some 22 as even the eejit who fitted it knew it was too small.

 

[spraggo]

The outputs shown are an old rule of thumb which was (still is) used and is reliable for std systems where guys fitting them do not have the time to sit down and work things out.



Hi tamz
So what you are saying is, that it does not matter whether the pipe is 100ft long or 10ft long, it will carry the same capacity.

Regards
spraggo