EXPLAIN THE SCIENCE BEHIND COMBI BOILER WORKING

[Skan]

Hi esra_ptrap,

Congradulation!!!

I have finally met a true professional ? academia?

By the way, are you a graduate with a 1st degree or may just one of the many degrees or even a PHD?

Have to go now & will be back to digest your enlightment.

Thanks
Why does my boiler shake??

 

[meldrew's_mate]

esra_ptrap, where do you get the symbol for "rho"?

And how do you get to quote other's text in small blocks?


Skan, you STILL haven't elaborated on the make & model of your boiler, nor the specifics of your boiler shake. Some might think you're a timewaster or taking the p.i.s.s.

 

[ChrisR]

Skan don't worry there are lots of degrees and much higher qualified on this site.
But it doesn't take a degree to work out that we need to know what the b....dy boiler is and where the bl...dy noise is coming from, does it?

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Ooops I'm obviously not high enough qualified to see you've already been asked...

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þµº¶¼ are OK but I cant do a rho either!

What's the Code button for?

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esra-ptrap this
[code:1]This equation also explains the tides by the way as the Moon travels around the Earth it's spatial relationship between the equatorial boundaries causes miniscule variations to it's gravitational constant which creates pressure differences in our seas ... Water flows from high to low pressure and hence the movement of the water we know as tides. [/code:1]

is wrong, clearly.

 

[megawatt]

Surely I'm not the only one who's realised esra's havin a larf (and I ain't a plumber)

gravitational constant of the universe (0.34)

I don't think even Stephen Hawking has worked this one out yet

You should notice that the shaking will be far more pronounced when the moon is at its highest orbit and full Moon's are notorious for causing boiler shake.

Nice one Esra gave me the best laugh I've had all week.

 

[esra_ptrap]

Yes, sorry guys but I couldn't help myself

I intermingled some imagination with the facts to see if Skan would take the bait, didn't expect the pros to run with it though

I wonder if his tutor would have noticed or given him full marks

For those who wondered what the rho symbol is ... It is an italic p ( p )

 

[PaulAH]

Look here, you rotten lot. This guy sounds genuine.

He may not speak good English but something tells me he really wants to know. Whether it's to pass an exam or just gain a better understanding of his boiler doesn't matter. For those who enjoy learning there are few things more irritating than the "don't worry your pretty little head" brigade. If that is your attitude, then why contribute to a site like this in the first place? The oft-derided Oilman, pompous though he can be, has never once gone down this line, which is why I like him.

Give the guy a break. I wish I could help him but I, like many others who appear on this site occasionally, do not have the authority to do so. I'm just grateful for the advice I have received from the more sensible members of this forum.

Paul

 

[megawatt]

PaulAH: Lighten up, a little good natured humour never hurt anyone.

If you find yourself working on a large site with lots of other pro's a sense of humour and the ability to laugh at yourself is a pre-requisite and will certainly help to maintain your sanity

 

[PaulAH]

So true. I can laugh at myself like any other incompetent. Laughing at others is a different matter.

Talking of which, what happened to the pillock Traineegasman? Was he, like a number of other unemployed Scousers, flown out to New Orleans to help with the looting operation?

 

[Skan]

Hi all,

Sorry for the delay, Weekend is a bit of a hectic time with the young family.

Glad to see such a healthy response!!

For record purposes, I did not take the bait.
But you cruel B******
Some other who view the forum could have thought you are a genuine pro & poor DIY guy could wreck his home thanks to some "Good" humour at expense of others.

I apologize for my poor english too & my IT ability. not all of us are brought up having computer in the house and all the gadgets. Some of us do have to work from a very young age to earn so as to supplement the income for the others in the family.

Oh! I appreciate and respect those who have to work & study to enhance one position in life. Just because you get a few letters behind your name or worn a square hat means that you know everything.

An old wiseman once told me "Respect is earned and one can not claim for himself, only if others say/pay you the respect then it is a of any significant.

Anyway enough of these "B*** S***"

Can I kindly request that those who are not serious regarding the understanding how the boiler work & resolving problem, could you all please keep your view to yourself or start another thread where you can discuss your view regarding this tread or else keep "QUIET"

I have got problem here which need solving and the cold weather is here.
I do not want the boiler to break down in the middle of winter and the family go cold & I have to get a guy in to replace the boiler charging me an arm & a leg. My hands are tied then too.

For those who can assist me, this is the information
It is a Halstead Finest Gold combi boiler.
Wall hung on a plasterboard partition wall separating the kitchen and bathroom.
The flue came off the boiler at the top, 90 deg elbow to the left, 280mm enter wall(350mm thick), emerge from the other side, 300mm away, turn 90deg elbow up, 250mm up penetrate a 25mm polycarbonate conservatory roof( pitching at 30deg??), on top of polycarbonate roof is the external flue system.

The whole length is within the manufacturer allowable length 2300mm.

PROBLEM: When the CH is off, I turn on DHW tap, the boiler shake for say 15-20 seconds. then stop.

If CH is on, this problem does not exist.

As per my initial queries
I would like to understand how it work behind the boiler so I can deduce the problem & when a trademan comes, I can tell whether he is capable or not.

Thanks for all who had contribute, let us learn a little from those who can help.

 

[megawatt]

Skan,

There's nothing in Esra's post that could have lead an unsuspecting DIY'er to do anything which would wreck their home (unless the install a 60' flue I guess )

If it's genuine advice you want here goes ...

I do not want the boiler to break down in the middle of winter and the family go cold & I have to get a guy in to replace the boiler charging me an arm & a leg. My hands are tied then too.

Agreed that you need this sorting asap but who says you'll need to change the boiler?

I would like to understand how it work behind the boiler so I can deduce the problem & when a trademan comes, I can tell whether he is capable or not.

If you are going to wait until you understand enough about your system to correctly diagnose the problem winter will have come and gone.

You wanted advice, here it is ...

Most DIY'ers, if they attempt to self-diagnose boiler problems will inevitably go for the paths of least resistance and diagnose by replacement often costing more than a visit from a pro i.e. someone here says "replace the pump" and off you go £60 + maybe system drain down if there are no isolating valves and then you've a much bigger job than when you started ... Re-pressure, bleed and hope it all works at least how it did when you started This doesn't fix the problem and someone recommends you replace the expansion vessel and off you go again

Diagnosis is often more problematic and time consuming than resolution of the problem and to do this successfully you need both knowledge and experience.

You can certainly gain knowledge by reading and using forums like this but experience

Call in a pro, get them to diagnose the problem for you and quote for repair ... You can then decide how to proceed but at least you'll know what the problem is.

It will cost you less to diagnose the problem this way.

 

[ChrisR]

Problem may well stem from having it on a plasterboard wall. Get someone to turn it on with you pressing HARD into the wall as near the boiler as you can get, underneath. Water takes a different route when HW is drawn, otherwise it's all the same pump, same fan etc. See instrs, on the web.
If that's it, a highly technical (needs degree in environmental science and media relations) solution : make hole through Pboard, insert tube of builder's foam (fireproof variety) can, squeeeze. That'll fix the bugger.

I think the pump has a 1-2-3 speed switch. You should ONLY leave it on 3, but try 2 to see if the noise happens.

 

[Skan]

Hi ChrisR & megawatt,

Thanks for the feedback.

I got a Corgi man in and he had a look, spent 2 to 3hrs, looking at various parts in the boiler & decide that it could be the flue. Dismantled the flue(vertical part) and reassemble. problem still exist.

It is the Corgi man who suggested that I should change the boiler. Since apparently they will only install Condensing boiler now to replace.
He went away to look for a suitable replacement. After many many weeks & I have been chasing him for a propose replacemnet boiler, he told me a suitable replacement could be a Glowworm CXi 30.

I wanted a written quote and he did not come back so a few weeks later he gave me verbal quote inclusive VAT for £1800.
When the written quote came in a few more weeks later, it is either a Gloworm 30Cxi or a Worcester 30Si. Both with 2 90 bends, 2 vertical terminal & 2no 1m extensions. the quote is £1800 plus £350 (power flush to meet boiler manufacturer warranty and ontop VAT.

and.. and.. he mentioned that the vertical flue may have to move more than the 300mm away from the external wall, could be 500mm therefore a conservatory guy will have to be used to remove the polycarbonate roof & also to seal /replace the existing one.
I guess more £££££

So you see, I just want to know why & how it works so that I can understand what he is doing is reasonable or not .

In anycase my own suspision is the FLUE. that is why I am asking whether the enclosed kitchen because of the conservatory have any effect on the boiler. Could air movement or restricted air have something to do with it?

My opinion is that the plasterboard wall should not have any effect since the shaking only last for 15 - 20 seconds then no more.

That is also why I asked is the incoming water supply have any effect?size of pipe or pressure or velocity.
That is also why I asked whether gas supply have any effect?size or pressure or velocity
.
My suspision is the flue and I have checked the allowable length of the flue & confirm that it has been installed within the allowable flue length.

What does the Restricting ring do?
Should it be inserted or not in the configuration set?

How does the flue work? or the science behind it?
Can the fan sort of start before the gas fire up therefore pull in more air and push out the stagnant flue?? in the flue first?


For your info, actually I do not actually want to tackle it myself (DIY) since it is a little more risky than plumbing. the effect of a mistake or poor DIY could blow the house up or worst suffocate the whole family, Yeh??

What do you think and can I check to confirm my suspision?

Thanks

 

[ChrisR]

Quote sounds a bit high to me. Where are you?

Are sure if the corgi man checked the burner presure on HW demand. He should have, but y'know..
Flue restrictor rings are there to ensure the flue gases go through the boiler at the right speed, so no fiddling.

When you run HW mode there's more gas neing burnt than on CH, so I (being a corgi) would be in there while it's running to see where exactly the noise comes from. Can't advise you do that. Someone who has the info in front of him can make it do things it normally wouldn't just to see if the noise happens. The obvious one is to turn the water on with the gas off - you get the same water flow.

May it be not vibrating at all but the burner making an odd noise? Can happen, even squealing noises!

I'd be trying to FEEL the vibration, be it water, or flue gas, or whatever. I'd hope isolate it using a mechanic's stethoscope.

Doessn't take any science, just the Mfrs Instrs which are actually quite good (on line too) and some deduction.

 

[Skan]

Hi,

I thought the quote was high too. How much do you think is reasonable?
Dismantle existing boiler & flue and reinstall new boiler & flue.
How much you think for dismantling?
How much you think for the new system?
I am from the the Midlands.

Well, I do not know whether he check the burner pressure or not & as you know, what he do I do not know & sometimes it is difficult for me to see exactly what he is doing.

I just remember that after he took off the front white panel & the inner cover plate, he tested the DHW. the boiler did not shake as violently but sort of a "Whoopp...whooop... whoop...whoop.." vibrating action come from the part where the wire heat the zig zagging pipes!!

So in my case the restricter ring need to be install or not?

What else can I do now?

 

[Softus]

...The oft-derided Oilman, pompous though he can be, has never once gone down this line, which is why I like him.

Really PaulAH? Never? Not even once? How's about this one:

//www.diynot.com/forums/viewtopic.php?t=33513&start=0&postdays=0&postorder=asc&highlight=cellar

Give the guy a break. I wish I could help him but I, like many others who appear on this site occasionally, do not have the authority to do so. I'm just grateful for the advice I have received from the more sensible members of this forum.Paul

Hear hear!