How to clean heat exchanger

[Janz]

Hi,

reading all the related post and the stuff that I already tried I really think that the "Heat Exchanger" of our "Worcester 24i Junior" (not greenstar) needs to be cleaned or even replaced.
I have looked at it but it seems to be inpossible to take the "Heat Exchanger" out of the boiler... please does anyone know how to do it?

Thanks a lot
Regards
Janz

 

[PowerFlushAssoc]

You can power flush the primary heat exchanger without removing it. You can either connect the power flush machine directly onto the boilers flow and return or you can connect into a radiator and close all but one other radiator, this will force the flow through that exchanger.
For the secondary or plate heat exchanger you will need to remove it and chemical clean / power flush / replace.

 

[Janz]

Hi, thanks for the tip.
Please, if I do this, where the 'rubbish' will go Or, should I turn on taps on when I'm doing it?
// I think the problem is in Primary heat exchanger - since before the boiler stopped working it was really noisy, watter was boiling like crazy a we heard that the air is there.
Thanks a lot

 

[Janz]

+ One more question please.
If I remove the "Heat Exchanger", what chemicals I need for cleaning the scale etc? Is the 'Concentrated Custic Soda' Strong enough?
Thanks

 

[SimonJohns]

By the sounds of this you have a little bit of knowledge. And to be totally honest it would be cheaper for you to get a GSR in an have them to do a proper diagnosis.

 

[Janz]

Hi Simon,
thanks The problem is that I haven't got money at all, so I'm facing only two options...
A, to try it by myself or
B, facing very could winter ;(

 

[SimonJohns]

Hi Simon,
thanks The problem is that I haven't got money at all, so I'm facing only two options...
A, to try it by myself or
B, facing very could winter ;(

Why don't you first explain the symptoms and we'll see if there's another way of helping you

 

[nysk2008]

what ever you do if you remove the (the kebab looking thing) please make sure you replace the gasket

 

[yo1]

one question, may be a bit unrelated but and I am pretty sure what i understand is correct so also dont mean to waste anyone's time..
If the Worcester was a combi and you do a power flush on it. if its not running whilst your flushing the system will it only circulate through the secondary heat ex, and to circulate it through the primary the heating will have to be on the whole time?

 

[Janz]

Thank you Simon and others...
Basuically, first the problem was that the boiler was heating->boiling like crazy, I heard the air in the "Heat Exchanger" and the presure went up to the maximum... than it stoped working completely.
What is happening now? The boiler doesn't light up and I know for sure that the Air pressure Switch
and Control Board are working fine.

Any ideas are very much appreciated! Thank you guys!

 

[mikegas]

one question, may be a bit unrelated but and I am pretty sure what i understand is correct so also dont mean to waste anyone's time..
If the Worcester was a combi and you do a power flush on it. if its not running whilst your flushing the system will it only circulate through the secondary heat ex, and to circulate it through the primary the heating will have to be on the whole time?

To get to the secondary heat ex it has to go through the primary

 

[Janz]

one question, may be a bit unrelated but and I am pretty sure what i understand is correct so also dont mean to waste anyone's time.. ...

Good question... I don't know!?

 

[nysk2008]

to be fair, save your fingers typing and and a gsr engineer in, we cant second guess everything. if not hope you get advice and good luck, hope you get it sorted.

 

[Billy Bob Bob]

what ever you do if you remove the (the kebab looking thing) please make sure you replace the gasket

different boiler its not a greenstar

 

[yo1]

"To get to the secondary heat ex it has to go through the primary"

ok, just read my post also and saw it didn't make sense there, the power flush will circulate through the primary heat x only when heating is on, when hot water is on it will not circulate through the primary as the div valve will not allow it too so there for if the boiler is off or not on heating mode you will not be flushing the boiler.. or am i in correct and the div valve will not effect flow through the main heat like this x?

 

[mikegas]

i think it would depend on the type of diverter valve, a pressure differential diverter valve would go through the boiler if it was off you would prob need to remove the diverter head on others

 

[yo1]

thanks.
is that because there is no pressure differential created by the hot tap been open and the valve would then not move over maybe..

 

[mikegas]

yeah. it may be that all other diverter valves are open to ch when off as well, unless it was in dhw mode when the power was cut, not sure, im sure someone will tell us

 

[yo1]

hope so, I thought they all stayed in hw but there you go.

 

[REDSAW]

The problem is that I haven't got money at all, so I'm facing only two options...
A, to try it by myself or
B, facing very could winter ;(

or;
a, face a very cold winter
by,
b, trying to fix it yourself.
and causing twice as much damage/cost than there is in the first place?.....

 

[Dannypipe]

Seriously, save money by DIYing something else. Don't start pulling your boiler apart. You aren't trained, qualified or experienced. Please, find the money and get a Registered Engineer in.

 

[Janz]

Thanks for your posts guys....

 

[fastnova]

Dont know if anyone has said this yet but there is no secondary heat exchanger or diverter valve on a 24i..

Loosely, it works like a water heater on hot water and runs the pump for the heating.. (has a separated main heat exchanger for the two)

again sorry if someone has said this already, but i didnt see it whilst reading through..

And agree if it has been boiling up and getting potentially dangerous then you need to call a knowledgeable engineer, try and see if you can get a free quote for the work, some company's will do this..

 

[fastnova]

Just wanted to say the most common problem with overheating in this boiler is the pump being faulty (not cooling the boiler after running the hot water this is very important) and the hot water temp sensor. It also has a manual overheat reset not electronic..

Would still advise a professional to diagnose and repair this problem though..

 

[yo1]

you say a 24i combi it dosent have a hot water heat exchanger or div valve?

 

[fastnova]

Sorry the junior has the electronic overheat reset on the pcb not the manual red plastic button on the standard 24i.

 

[yo1]

fastnova is there not a secondary heat exchanger in a 24i junior?

 

[fastnova]

no diverter valve and the heat exchanger above the burner is the only one, it does both the hot water and heating. (has two seperate parts to it, ie. water is not mixed)

 

[yo1]

which worcester 24i junior are you talking about then?

 

[fastnova]

im taking this on the fact it is just a 24i junior rsf, not a greenstar? 24i junior rsf was discontinued in 2007...

 

[yo1]

ok, I thought it was a greenstar.

 

[fastnova]

Does the boiler have the controls on the front behind a drop down door, or are they exposed all the time? (greenstar behind door & standard 24i exposed)

 

[Janz]

Hi, it's not greenstar. The controls are exposed.
Thanks