Gas boiler Operating.

Joey the lips

Hi Folks...

Wondered if you can help. Was asked a question today i have not been asked in a while... Brother has a gas boiler thats 15 years old and sounds like its just about to set down...A couple of leaks...heatexchanger pump... etc...

Anyway traditionally what i would have done there is supply a boiler with a cast iron heat exchanger somethine like a suprima or a glowworm. You know why..the dirt etc...

Just wondering since condensing boilers have come in the standard seems to be aluminium heat exchangers which off course is prone to blocking...or are they...


The simple question i am asking is...what is now supplied for the retrofitting of a boiler...is it a condensing one with a fabricated heat exhanger and a serious system flush or is it something else...

Many thanks for parting with the knowledge....

knighted_1

condensing boiler - fit a magnacleanse , cleanse and inhibitor -

above is not worth a fcuk unless the gas installer gas rates the appliance as most that were fit are overfiring and thats why the heat exchanger cracks and leaks

yoshytoshy

It doesn't take a lot to clean heating systems. Glowworm and worcester have large openings within the exchanger.
Boilers like baxi megaflo ,have a smaller bore exchanger and the system needs to be powerflushed before they're installed.
I've been to technical courses for a lot of boilers and I've seen the inside of exchangers and other parts etc.

Getting a 15kw boiler is better for replacing existing boilers in most houses as the 24kw needs a lot of gas ,larger pipe.

heinbloed

The (modulating) condensing boilers come equipped with their own build-in heat exchangers. As being part of the condensing modus at which they run efficiently these shouldn't be altered.

There are various types of materials, what we look at being aluminia could be an alloy with far better corrosion resistance at the combustion side than the very cheap aluminia ones. I'm not sure if aluminia on its own is still used for this purpose.
The combustion heat exchanger should be inspected and cleaned anyhow once per year, it's part of the anual service and important for the efficient and safe operation.
Some manufacturers use ceramic instead of alloys.
Clogging-up of heat exchangers ( the primary/central heating loop) can be avoided by a mud-trap at the lowest point.



The installation issue itself asks for a flue system suitable for condensat to drain-off. Standard flues designed for higher temperatures don't allow for this, the condensate issue didn't arise with the old boilers.

Check first how the new flue will be integrated, the shortes way(straight through the wall) might not be available, the lining of the old flue can be done but is more labour- and material intensive ...

yoshytoshy

heinbloed wrote: »

The combustion heat exchanger should be inspected and cleaned anyhow once per year, it's part of the anual service and important for the efficient and safe operation.

This is wrong for a lot of condenser heat exchangers ,some have a silicone mixture that can be damaged if scraped.

It's important if people give advice on this forum that they know what they're talking about.

heinbloed

Please publish a link to this 'information', yoshytoshi.

The combustion chamber MUST be inspected (and cleaned if necessary) at EVERY inspection. It is a vital part of the job, vital by it's very means.

The heat exchanger IS part of the combustion chamber.....

Further on the ENTIRE flue must be visually inspected and cleaned at each inspection.

The heatexchanger is part of the flue.....

"
It's important if people give advice on this forum that they know what they're talking about. "

Why is that important, yoshytoshy?

knighted_1

yoshytoshy wrote: »

.

It's important if people give advice on this forum that they know what they're talking about.

lets see if you do - you recomended a 15kw boiler - how many cubic metres per hour would that use or call for ?

yoshytoshy

knighted_1 wrote: »

lets see if you do - you recomended a 15kw boiler - how many cubic metres per hour would that use or call for ?

I've a better one for you ,whats the maximum lent of 15mm copper allowing 1.5 cubic metres of gas ?

yoshytoshy

heinbloed wrote: »

Please publish a link to this 'information', yoshytoshi.

Why is that important, yoshytoshy?

I couldn't two flying hoots ,whether I post on this forum or not.

Good luck.

heinbloed

heinbloed wrote: »

Further on the ENTIRE flue must be visually inspected and cleaned at each inspection.

Why?

heinbloed

Gary71 asks why the flue of a combustion device should be inspected ...

Anyone out there? Yoshytoshy?

slavetothegrind

heinbloed could you please calm down a bit, you are managing to raise everyones hackles here whether you realise it or not.

You have stated previously you are not a plumber where others here are well experienced professionals, if you question their opinions please do so with respect and we'll all learn something in the process.

Every day is a school day for most of us:)

OP, if it were me I would be thinking about a good heat pump, failing that flush, flush and flush again it's not all about the heat exchanger other bits get shagged as well, +1 for the magnaclean with the larger connections and go with something with a long warranty, i can pm you with where you can get a decent boiler if you unsure about the stuff you sell:pac:

yoshytoshy

gary71 wrote: »

i can pm you with where you can get a decent boiler if you unsure about the stuff you sell:pac:

What boilers do you work on most gary ?

I'm a worcester fan myself.

knighted_1

yoshytoshy wrote: »

I've a better one for you ,whats the maximum lent of 15mm copper allowing 1.5 cubic metres of gas ?[/QUOTE

who said anything about 15mm

if you put 1.5 m3 in to your 15 kw boiler you are going to overfire it by 2 kw -
1.5 x 11.39 = 17.08kw

yoshytoshy

knighted_1 wrote: »

yoshytoshy wrote: »

I've a better one for you ,whats the maximum lent of 15mm copper allowing 1.5 cubic metres of gas ?[/QUOTE

who said anything about 15mm

if you put 1.5 m3 in to your 15 kw boiler you are going to overfire it by 2 kw -
1.5 x 11.39 = 17.08kw

You've lost me ,seriously.

Boiler fans dictate the volume of gas going into a boiler ,apart from that it's the pipe that dictates it.

If you're going to start talking about rating a boiler etc. ,any boilers I've installed for the last three years are condensing.

yoshytoshy

yoshytoshy wrote: »

What boilers do you work on most gary ?

I'm a worcester fan myself.

I bitch way to much to say, if the fruit loops find out I'm moaning about them here then they won't buy my boilers(which are bloody good).

Joey the lips

Right that has been a fair deviation.....

So is the answer that there is no cast iron heatexhangers available in condensing boilers so the only way to go is

Flush Flush and flush again...

which off course will no doubt cause a pin hole leak some where obsecure so off course dont forget the leak sealer....

heinbloed

....So is the answer that there is no cast iron heatexhangers available in condensing boilers so the only way to go is

Flush Flush and flush again...

which off course will no doubt cause a pin hole leak some where obsecure so off course dont forget the leak sealer....

Well, the condensing boiler's heat exchanger is the last thing that would fail because of rust, in a rust-prone installation....
If the rest of the system is made of brass or stainless steel or of a similar corrossion restitant material then no inhibitor or flushing is necessary.

There would no build-up of sludge in the best case scenario.

My own central heating system (condensing boiler with alloy heat exchanger) has never had anything but clean drinking water, straight from the well.
And is running since 7 years like that. No flushing, no inhibitor, sometimes topping up the pressure. With clean drinking water.

Joey the lips

heinbloed wrote: »

Well, the condensing boiler's heat exchanger is the last thing that would fail because of rust, in a rust-prone installation....
If the rest of the system is made of brass or stainless steel or of a similar corrossion restitant material then no inhibitor or flushing is necessary.

There would no build-up of sludge in the best case scenario.

My own central heating system (condensing boiler with alloy heat exchanger) has never had anything but clean drinking water, straight from the well.
And is running since 7 years like that. No flushing, no inhibitor, sometimes topping up the pressure. With clean drinking water.

Please understand....i am not asking you about yours. I am asking a direct simple question.

In a boiler retrofit where traditionally because of build up of sludge etc when a boiler was changed usually one with a cast iron heatexchanger was used...

What is the procedure now seen as though a lot of the condensing boilers dont seem to have them..

Joey the lips

Joey the lips wrote: »

What is the procedure now seen as though a lot of the condensing boilers dont seem to have them..

Requirements havn't changed, people's understanding has, if you put a Potterton Netaheat on a dirty system your going to have issues. Your right a modern bolier has to have clean system water, so have a look at the water if you have no signs of sludge or solids you may get away with a cleaning chemical and then flush asper manufactures instructions, personally I would power flush and fit a magnaclean as a given.

Joey the lips

gary71 wrote: »

Requirements havn't changed, people's understanding has, if you put a Potterton Netaheat on a dirty system your going to have issues. Your right a modern bolier has to have clean system water, so have a look at the water if you have no signs of sludge or solids you may get away with a cleaning chemical and then flush asper manufactures instructions, personally I would power flush and fit a magnaclean as a given.

So really its use a new boiler and possibly powerflush....

Has anyone any experience how a pex system responds to a power flush.

Just while I am asking.

knighted_1

yoshytoshy wrote: »

knighted_1 wrote: »

You've lost me ,seriously.

Boiler fans dictate the volume of gas going into a boiler ,apart from that it's the pipe that dictates it.

If you're going to start talking about rating a boiler etc. ,any boilers I've installed for the last three years are condensing.

so ,when you install a condensing boiler what do you do ? do you not gas rate it ?

knighted_1

knighted_1 wrote: »

yoshytoshy wrote: »

so ,when you install a condensing boiler what do you do ? do you not gas rate it ?

I don't, I'd like to know why you do.

knighted_1

gary71 wrote: »

knighted_1 wrote: »

I don't, I'd like to know why you do.

because its the law? IS 813 section 15.1 - comissioning appliances

three lines down

-that appliances are adjusted to thier correct gas rate

knighted_1

knighted_1 wrote: »

gary71 wrote: »

because its the law? IS 813 section 15.1 - comissioning appliances

three lines down

-that appliances are adjusted to thier correct gas rate

How would you adjust a codensing boiler?

knighted_1

on the throttle on the gas valve ,where would you throttle back ?

knighted_1

knighted_1 wrote: »

on the throttle on the gas valve ,where would you throttle back ?

I don't, I have a working pressure of 20 mbar and a fan controlled by the pcb, you can on some boilers mess with the fan speed but it's not advisable as it can effect flame picture and stability if done incorrectly.

(setting the co2% is a given)

knighted_1

gary71 wrote: »

I don't, I have a working pressure of 20 mbar and a fan controlled by the pcb, you can on some boilers mess with the fan speed but it's not advisable as it can effect flame picture and stability if done incorrectly.

you really should upskill gary -nothing to do with the fan speed its to do with the volume of gas multiplyed by the calorific value(11.39) to get the kw input (most manufacturers set the rate at the english calorific value 9) post any boiler make ,give me the kw and the manufacturers recomended gas rate on max and i will show you why they overfiring

http://www.boards.ie/vbulletin/showthread.php?t=2055804301&page=2

ring martin and ask him how to set up a condensing boiler -he told me most people setting them up wrong (or not setting them up) thats why they overfiring

edit - i googled martin and the first result is a post by you about him so i presumed you know him

knighted_1

knighted_1 wrote: »

you really should upskill gary -nothing to do with the fan speed its to do with the volume of gas multiplyed by the calorific value(11.39) to get the kw input (most manufacturers set the rate at the english calorific value 9) post any boiler make ,give me the kw and the manufacturers recomended gas rate on max and i will show you why they overfiring

http://www.boards.ie/vbulletin/showthread.php?t=2055804301&page=2

ring martin and ask him how to set up a condensing boiler -he told me most people setting them up wrong (or not setting them up) thats why they overfiring

edit - i googled martin and the first result is a post by you about him so i presumed you know him

yep, I know him very well so you should ask him about my skill set, as for up skilling I try to do that every day so I'm more than happy for you to tell me where I'm going wrong.

knighted_1

well i did try - either he trained me wrong or you are right - you tell me which
i dont doubt your skill set but not gas rating a condensor boiler is wrong and if you ask him you could clear up weather i am wrong and you are right -

knighted_1

knighted_1 wrote: »

well i did try - either he trained me wrong or you are right - you tell me which
i dont doubt your skill set but not gas rating a condensor boiler is wrong and if you ask him you could clear up weather i am wrong and you are right -

You are doing a ajustment outside of manufactures instructions, there is a good chance you will be going below 19 mbar working pressure, you are setting the boiler by keeping it firing high when it would modulating down due to the over juiced gas, as a manufactures tech I have never had a problem with over cooked boilers but that doesn't mean it's not a problem and my training as a British Gas engineer means I look at gas rating differently.

knighted_1

knighted_1 wrote: »

clear up weather i am wrong and you are right -

I don't see it as a competition and I don't pretend to have all the answers, everydays a learning day.

yoshytoshy

knighted_1 wrote: »

well i did try - either he trained me wrong or you are right - you tell me which
i dont doubt your skill set but not gas rating a condensor boiler is wrong and if you ask him you could clear up weather i am wrong and you are right -

Theres no rating on new condenser boilers ,on some condensers that are a couple of years old you have to adjust the gas valve slightly on low fire and high fire.
And only if the C02% is out.

knighted_1

i apoligise if i came across wrong .that wasnt my intention -share the knowledge
it is the only part of manufacturers specs that is actually wrong (in this country nowhere else ) as our calorific value is much higher than the uk we at 11.39 - uk is 9.2 ? - if you do the equation on kw divided by m3 of gas you will end up with a figure very close to the uk calorific value - if you do same equation for ireland you will find that we are overfiring by 15 to 25 per cent because of the 11.39 figure - manufacturers state you can overfire by plus or minus 5 per cent

if we over fire by this much we put the co levels much higher than manufacturers allow so in theory we must throttle down to get the levels correct and safe - this can be done with the analyser connected and just adjust - there is no problem running a boiler on 12 or 13 milibar as that is quite normal ,once there is 20 milibar standing presure (regulations) - we cant measure other side of a zero rated valve and thats where a lot of confusion takes place with installers ,they think the boiler gas adjustments itself ,but it doesnt .
this is where the IS 813 regs come in section 15.1 about gas rating all appliances .installers are leaving potentially letal installs in houses if they dont gas rate and analyse during the commissioning of a new install

again i apoligise if i came across bad ,but i try hard to keep my standards extremly high and prob have a bit of a communication problem

Micky Dolenz

Lads keep it civil.

If we can't talk like professionals don't bother posting here. This isn't a pissing contest.

yoshytoshy

I test every boiler I install ,check combustion and gas rates and even the flow and return temperature. I've been filling out the log books for the last couple of years ,so you have to take all these readings.

I've yet to see any boiler fire outside the manufacturers specifications when fired up for the first time.

The problems only arise when the boiler has been in use for a couple of years ,because the co2 can increase and dirty up the boiler and this is when they need to be serviced intrusively.
If the C02 rates are intact ,it's almost certain that the boiler is clean inside. Otherwise the gas valve should be adjusted and guaranteeing the boiler runs clean.

It's important to inspect a condenser every year for combustion ratio ,make sure it doesn't start getting dirty.

Micky Dolenz

About the gas rating. I would gas rate every appliance that I look at.

In fact, on the RGI inspections that have been carried out on me, I have been asked to gas rate the appliances, one was a condensing boiler.

Another point, until consumer awareness increases, good installers will suffer. We power flush as standard and I have often tried to push a boiler buddy or similar on to clients. Power flushing means we take more time than most to change a boiler, approx a day longer.

doing things right means extra €€€'s. Unless you have a client in the know, it can be very hard to sell.

yoshytoshy

Micky Dolenz wrote: »

Another point, until consumer awareness increases, good installers will suffer. We power flush as standard and I have often tried to push a boiler buddy or similar on to clients. Power flushing means we take more time than most to change a boiler, approx a day longer.

Micky powerflushing is not needed for a lot of heating systems ,chemically cleaning is adequate and have been told that ourselves by more than one manufacturer.

Theres no need for magna cleans and all them other gadgets if the system is operating properly.

In case anyone wants to criticise me for saying that ,our company is known to be one of the biggest buyer of cleaners and chemicals and have been for years.

Micky Dolenz

yoshytoshy wrote: »

Micky powerflushing is not needed for a lot of heating systems ,chemically cleaning is adequate and have been told that ourselves by more than one manufacturer.

Theres no need for magna cleans and all them other gadgets if the system is operating properly.

In case anyone wants to criticise me for saying that ,our company is known to be one of the biggest buyer of cleaners and chemicals and have been for years.

I am not criticising you.

In my experience nearly all system need a good clean because inhibitor was rarely used here, up until recently. Most retrospect installations are on systems 10 years and older.

yoshytoshy

Micky Dolenz wrote: »

I am not criticising you.

In my experience nearly all system need a good clean because inhibitor was rarely used here, up until recently. Most retrospect installations are on systems 10 years and older.

It's funny you should say that ,i was cleaning out our stores lately and found an ancient container of inhibitor, it must have been over twenthy years old:D

Correct burner pressure or correct co2 setting = correct gas rate, I use gas rating as proof of what I already know from testing it's a tool, not a necessitie,
nothing less than 19mbar at the appliance working pressure 1 mbar drop allowed, there is no problem getting the correct co2 at the correct working pressure and your on your own ajusting boilers in away not reconised by the manufactures ie. me, you reduce the gas to a low working pressure then any igniton issues you be fixing because I'll be looking for more gas before I get involved, Viessmann work at 11mbar working pressure allday everyday and that's the main boiler Martin has worked on the other is mine and I would be telling him the same thing, lastly no need to apolagise, gas fitting comes done to opinions and we all have one

Micky Dolenz

Micky Dolenz wrote: »

RGI inspections .

Inspections me arse, they thought I was dangerous.

Micky Dolenz

gary71 wrote: »

Inspections me arse, they thought I was dangerous.

:P

Joey the lips

Thank you folks.... I have learned nothing....

Joey the lips

Hi Folks...

Changed the title of the thread.... You are free to discuss boiler operating....etc...

Enjoy.....

knighted_1

gary71 wrote: »

Correct burner pressure or correct co2 setting = correct gas rate, I use gas rating as proof of what I already know from testing it's a tool, not a necessitie,
nothing less than 19mbar at the appliance working pressure 1 mbar drop allowed, there is no problem getting the correct co2 at the correct working pressure and your on your own ajusting boilers in away not reconised by the manufactures ie. me, you reduce the gas to a low working pressure then any igniton issues you be fixing because I'll be looking for more gas before I get involved, Viessmann work at 11mbar working pressure allday everyday and that's the main boiler Martin has worked on the other is mine and I would be telling him the same thing, lastly no need to apolagise, gas fitting comes done to opinions and we all have one

you see this is the thing ,a gas rate is required by law now .if as suggested earlier that someone hangs a boiler and fires it up i gaurantee it will be overfiring if someone wants to post a boiler make and kw and the manufacturers stated m3ph i will do the calculation and show you how its overfiring -

knighted_1

knighted_1 wrote: »

you see this is the thing ,a gas rate is required by law now -

your right

knighted_1 wrote: »

if as suggested earlier that someone hangs a boiler and fires it up i gaurantee it will be overfiring -

based on what studies, what are your gas qualification(apart from GID) and what have you studied to come to this opinion(apart from Mr Hogan).

slavetothegrind

http://www.ferroli.co.uk/Product_Documentation/Domestic/Optimax_HE_18_S_Manual.pdf

in the case of the above boiler, you install it and check you have the required 20mb at the inlet. no further adjustment of gas pressure is allowed as the valve is sealed.
how do you propose to correct the overfire situation you believe to exist here?

me up for learning:D

Micky Dolenz

slavetothegrind wrote: »

http://www.ferroli.co.uk/Product_Documentation/Domestic/Optimax_HE_18_S_Manual.pdf

in the case of the above boiler, you install it and check you have the required 20mb at the inlet. no further adjustment of gas pressure is allowed as the valve is sealed.
how do you propose to correct the overfire situation you believe to exist here?

me up for learning:D

The baxi solo HE is the same, and there are a few others where there is no adjustment. If you find a problem with appliance firing etc when commissioning it, you would have to make a service call.

Micky Dolenz

Micky Dolenz wrote: »

The baxi solo HE is the same, and there are a few others where there is no adjustment. If you find a problem with appliance firing etc when commissioning it, you would have to make a service call.

Don't go mixing up a real ignition or combustion issue with a made up over firing issue.