Central heating leak sealer

MOTM · 18-11-2013 3:13pm #1

We've a leak somewhere in our central heating system. Losing .1 bar every couple of days. If I can't find the leak, is it worth trying leak sealer in the system (as suggested by our plumber)? Are there downsides to using it. The house is about 7 years old.

corkgsxr · 18-11-2013 3:22pm

They do work but some are crap some are brilliant.

I use repa-r 200 leak sealer. Its twice the price of most but iv seen it work on big leaks.

Only thing is it needs to be put in left to work then flushed out. Or else it does stuff like stop pumps

Billy Bunting · 18-11-2013 3:24pm

Get shane0007 out, he has a thermal camera that will locate the leak. He will also give you 30% discount if you mention me.

shane0007 · 18-11-2013 8:12pm

Billy Bunting wrote: »

Get shane0007 out, he has a thermal camera that will locate the leak. He will also give you 30% discount if you mention me.

Funny, but wearing thin now.

OP, has the expansion vessel pressure being checked & confirmed to be ok, i.e. water drained & vessel pressure checked with no system pressure against it?

anthonyos · 18-11-2013 8:19pm

I think seak sealers are a mugs game there is only one way to fix a leak and that is to find it and repair it or find the area that it possibly could be and replace the pipe work

Billy Bunting · 18-11-2013 8:33pm

shane0007 wrote: »

Funny, but wearing thin now.

k, we'll stick to the 20% then

.

Show your amusement

shane0007 · 18-11-2013 8:37pm

Billy Bunting wrote: »

k, we'll stick to the 20% then

.

Show your amusement

Have you relocated to Cork or somefink?

:D:D:D

MOTM · 18-11-2013 8:53pm

shane0007 wrote: »

Funny, but wearing thin now.

OP, has the expansion vessel pressure being checked & confirmed to be ok, i.e. water drained & vessel pressure checked with no system pressure against it?

No, not yet. I'll mention it to the plumber. Thanks.

MOTM · 18-11-2013 8:56pm

anthonyos wrote: »

I think seak sealers are a mugs game there is only one way to fix a leak and that is to find it and repair it or find the area that it possibly could be and replace the pipe work

In what way are they a mugs game? Unfortunately the boiler is in the detached garage and replacing pipework might be a bit difficult. Is it that leak sealer just doesn't work?

anthonyos · 18-11-2013 9:01pm

I have used it loads of time and not once has it worked for me but worth a shot if your stuck

shane0007 · 18-11-2013 9:05pm

MOTM wrote: »

No, not yet. I'll mention it to the plumber. Thanks.

That's the first thing I would check.

Leak sealers are very hit & miss. They react with oxygen & can be problematic for many systems. Many boiler manufacturers will void the warranty if used.

I would always only use a leak sealer as a very last resort, & even then it generally doesn't work.

18-11-2013 10:45pm

I hate leak sealer, selling a dream but tends to end in a nightmare.

corkgsxr · 18-11-2013 10:46pm

In fairness the cheap ones iv never seen them work. Repa-r is the only one id use.

Had one aunt in law thats half broke. 3 rads pinholed. 300 euro worth of rads. 70 euro bottle of repa and all sealed. Still holding 2 years later. Handy cheap solution.

MOTM · 19-11-2013 8:03am

Update: found a small leak on one rad connection and possibly one (also small) in the hot press. Will fix those first and see if that solves it.

mrcheez · 04-07-2014 12:58pm

Sorry to open an old(ish) thread, but I have a similar problem where the pressure is dropping in my system every few days.

The plumber suggested that he use Fernox Leak Sealer (http://www.fernox.com/products/water+treatment+chemicals/leak+sealers)

Is this any good?

I'll also contact Worcester Bosch to ensure that using this won't void my boiler warranty.

Dtp1979 · 04-07-2014 1:20pm

mrcheez wrote: »

Sorry to open an old(ish) thread, but I have a similar problem where the pressure is dropping in my system every few days.

The plumber suggested that he use Fernox Leak Sealer (http://www.fernox.com/products/water+treatment+chemicals/leak+sealers)

Is this any good?

I'll also contact Worcester Bosch to ensure that using this won't void my boiler warranty.

The fernox one isn't great to be honest. The only time I've had success is with oxypic but you should put it into the system after its cleaned. But the best advise is to try and find the leak

04-07-2014 1:29pm

mrcheez wrote: »

Sorry to open an old(ish) thread, but I have a similar problem where the pressure is dropping in my system every few days.

The plumber suggested that he use Fernox Leak Sealer (http://www.fernox.com/products/water+treatment+chemicals/leak+sealers)

Is this any good?

I'll also contact Worcester Bosch to ensure that using this won't void my boiler warranty.

Telling Worcester Bosch you're refilling your system every few days will have a bigger impact on your warranty than the leak sealer.

I wouldn't use leak sealer as it's cack and can at times impact on the boiler.

Find it, fix it, is the overall message from this thread, yes you may get lucky with a leak sealer but your still pouring cack in to your heating system.

mrcheez · 04-07-2014 1:35pm

Is there a way to detect where the leak is without lifting up all the carpet/floorboards/smashing through the concrete floor etc?

That would be a fun few days!

corkgsxr · 04-07-2014 2:57pm

Re-pa 200

70 euro a bottle but it really works

mrcheez · 04-07-2014 3:00pm

Cheers, back to the original question in #18, is there a detector that can find a leak without having to rip up boards/concrete?

Sleeper12 · 04-07-2014 3:52pm

Yes there is. There are dedicated companies that do leak detection. They charge €70 per hour (plus gas) & a lot of them charge a minimum of 4 hours.

I'd try rad seal chemicals first.:)

mrcheez · 04-07-2014 3:55pm

Cool, I'll get the RGI company to pay for it as the installation is less than a year old.

Dtp1979 · 04-07-2014 4:51pm

mrcheez wrote: »

Cool, I'll get the RGI company to pay for it as the installation is less than a year old.[
Did they install everything? As in the boiler, rads and all the pipework?

mrcheez · 04-07-2014 5:40pm

yessir

SmallBalls · 05-07-2014 5:05pm

Oxypic is good gear, always had success the few times I've used it.

mrcheez · 18-07-2014 12:02pm

gary71 wrote: »

yes you may get lucky with a leak sealer but your still pouring cack in to your heating system.

I'm going to go ahead with Oxypic, but I'm kind of worried about the mention of "your(sic) still pouring cack in to your heating system."

What is the "cack" in Oxypic? Is it not supposed to be a good thing to put in to the system?

Will it need to be redone in a few years, or are the fixes permanent?

I heard that it's best to put into the smallest rad in the system, I have one in the bathroom on a tiled floor, so I guess this will suffice?

I also have a Magna clean & inhibitor installed on the line, will this get damaged or interfere?

18-07-2014 12:39pm

mrcheez wrote: »

I'm going to go ahead with Oxypic, but I'm kind of worried about the mention of "your(sic) still pouring cack in to your heating system."

What is the "cack" in Oxypic? Is it not supposed to be a good thing to put in to the system?

Will it need to be redone in a few years, or are the fixes permanent?

I heard that it's best to put into the smallest rad in the system, I have one in the bathroom on a tiled floor, so I guess this will suffice?

I also have a Magna clean & inhibitor installed on the line, will this get damaged or interfere?

Leak sealer can at times have a negative impact on a gas boiler which can leave a warranty null and void.

I wouldn't use it in my house.

mrcheez · 18-07-2014 1:22pm

gary71 wrote: »

Leak sealer can at times have a negative impact on a gas boiler which can leave a warranty null and void.

I checked with Worcester Bosch last week and they said it wouldn't affect the warranty.

Why wouldn't you use it in your house? What specific damage could it cause?

18-07-2014 1:36pm

mrcheez wrote: »

I checked with Worcester Bosch last week and they said it wouldn't affect the warranty.

Why wouldn't you use it in your house? What specific damage could it cause?

Different manufactures have different opinions.

A gas boiler has the smallest thruways on a heating system which a sealant can at times have a impact on, also you find auto air releases can block.

I'm not a fan where others are so the choice is yours.

mrcheez · 18-07-2014 1:43pm

gary71 wrote: »

Different manufactures have different opinions.

A gas boiler has the smallest thruways on a heating system which a sealant can at times have a impact on, also you find auto air releases can block.

I'm not a fan where others are so the choice is yours.

I'm just making sure I'm asking questions now so I have a better understanding (I feel a forum with experienced plumbers would be better than spending hours searching the internet).

Assuming that the boiler itself doesn't become blocked, is there anything else that could potentially be damaged by a leak sealant, or could I assume it will run as normal?

I'm guessing such a blockage would be pretty evident, or would it be something subtle that I wouldn't see, but could be damaging the system slowly?

Dtp1979 · 18-07-2014 1:58pm

mrcheez wrote: »

I'm just making sure I'm asking questions now so I have a better understanding (I feel a forum with experienced plumbers would be better than spending hours searching the internet).

Assuming that the boiler itself doesn't become blocked, is there anything else that could potentially be damaged by a leak sealant, or could I assume it will run as normal?

I'm guessing such a blockage would be pretty evident, or would it be something subtle that I wouldn't see, but could be damaging the system slowly?

Another issue that would concern me is that you have inhibitor in your system. You're now going to add another chemical and mix both. Nobody knows how they will react I'm afraid

mrcheez · 18-07-2014 2:46pm

Just checked with Worcester Bosch there, Fernox F4 leak sealant is the only one they support the use of.

Any other sealant will void the 7-year warranty.

Is Fernox F4 completely rubbish?

Dtp1979 · 18-07-2014 4:17pm

mrcheez wrote: »

Just checked with Worcester Bosch there, Fernox F4 leak sealant is the only one they support the use of.

Any other sealant will void the 7-year warranty.

Is Fernox F4 completely rubbish?

Ye I'm afraid so. If you've fernox inhibitor then use their sealer

mrcheez · 18-07-2014 4:23pm

Dtp1979 wrote: »

Ye I'm afraid so.

Any harm in giving it a shot?

At least if it fails I'll have an excuse to ask the RGI to get proper leak-detectors in.

Dtp1979 · 18-07-2014 4:44pm

mrcheez wrote: »

Any harm in giving it a shot?

At least if it fails I'll have an excuse to ask the RGI to get proper leak-detectors in.

Get it in writing off Worcester Bosch first. Then work away

mrcheez · 18-07-2014 4:52pm

Dtp1979 wrote: »

Get it in writing off Worcester Bosch first. Then work away

Sorry get what in writing?

If you mean the Fernox thing, the communication was via email, so I've got that.

Dtp1979 · 18-07-2014 4:56pm

mrcheez wrote: »

Sorry get what in writing?

If you mean the Fernox thing, the communication was via email, so I've got that.

We'll if they say it's ok to use f4 then it'd be no harm to try

mrcheez · 24-07-2014 5:52pm

Is F4 really that bad?

All reviews I've found tend to say it works for small leaks:

e.g. http://www.amazon.co.uk/Fernox-F4-Superconcentrate-Leak-Sealer/dp/B00BJ71U3Y/ref=cm_cr_pr_product_top

K.Flyer · 24-07-2014 7:05pm

I have used F4 a few times. ... imo.. a waste of time and money.
I can safely say that I have had a 7 out of 10 single dose success rate with the Oxypic and no issues with the boiler later on.
But a few words on using Oxypic.
It can stain like a demon and the bottle is full to the brim, which makes it easier to spill.
Also the contents settle, so it gets heavy and gloopy at the bottom of the bottle.
I always go outside and give the bottle of Oxypic a good shake and divide it into two empty water bottles and then add some water to the bottles just to thin it out slightly and make it a bit easier to pour.

Dtp1979 · 24-07-2014 7:51pm

K.Flyer wrote: »

I have used F4 a few times. ... imo.. a waste of time and money.
I can safely say that I have had a 7 out of 10 single dose success rate with the Oxypic and no issues with the boiler later on.
But a few words on using Oxypic.
It can stain like a demon and the bottle is full to the brim, which makes it easier to spill.
Also the contents settle, so it gets heavy and gloopy at the bottom of the bottle.
I always go outside and give the bottle of Oxypic a good shake and divide it into two empty water bottles and then add some water to the bottles just to thin it out slightly and make it a bit easier to pour.

Exactly what I do too

corkgsxr · 24-07-2014 10:58pm

Dtp1979 wrote: »

Exactly what I do too

Me too only way.

If you get it on anything the only solution is burn the house down.

Also leaks from rads stain like Feck too.

mrcheez · 25-07-2014 8:19am

K.Flyer wrote: »

I have used F4 a few times. ... imo.. a waste of time and money.

Why exactly?

How can so many positive reviews be wrong (not just on this site, but do a google search)?

Are you saying that when they say it "fixed the leak" it really didn't?

Dtp1979 · 25-07-2014 8:27am

mrcheez wrote: »

Why exactly?

How can so many positive reviews be wrong (not just on this site, but do a google search)?

Are you saying that when they say it "fixed the leak" it really didn't?

We're not saying it doesn't work. We're saying it didn't work for us

mrcheez · 25-07-2014 8:32am

mrcheez wrote: »

Is Fernox F4 completely rubbish?

Dtp1979 wrote: »

Ye I'm afraid so.

Dtp1979 wrote: »

We're not saying it doesn't work.

I think you can see where I'm getting confused... anyway my faith is somewhat restored as clearly it works in some situations and considering my leak is so small (approx 0.1 bar every 1-2 weeks) it could work.

But the RGI did hint that they would hire the proper inspectors if it fails.

Dtp1979 · 25-07-2014 9:02am

mrcheez wrote: »

I think you can see where I'm getting confused... anyway my faith is somewhat restored as clearly it works in some situations and considering my leak is so small (approx 0.1 bar every 1-2 weeks) it could work.

But the RGI did hint that they would hire the proper inspectors if it fails.

It hasn't worked for me in the past. Therefore I consider it rubbish

K.Flyer · 25-07-2014 9:35am

mrcheez wrote: »

Why exactly?

How can so many positive reviews be wrong (not just on this site, but do a google search)?

Are you saying that when they say it
"fixed the leak" it really didn't?

What I am saying is that F4 has never worked for me. And on the occasions that I did use it obviously I got called back saying that there was still a problem. I have had better results using Oxypic.
However I will emphasis that I would always endeavour to locate and repair the leak before using any leak sealing solution. .

mrcheez · 25-07-2014 11:33am

K.Flyer wrote: »

However I will emphasis that I would always endeavour to locate and repair the leak before using any leak sealing solution. .

Seriously? Even if that means having to move out furniture (potentially leaving them exposed to the elements), rip up carpet, dig up concrete/open floors boards, etc etc

Surely if you can avoid this by first trying a leak-sealing solution it would be better?

K.Flyer · 25-07-2014 1:14pm

What I am saying is that I would be checking as much of the pipework and the installation as is possible without digging up floors.
And yes, depending on the rate of pressure loss, I would try the sealant before digging up a floor.

Mizuno Man · 17-01-2017 8:08pm

Ancient thread here I know - but it's one I read a couple of times while having problems recently with our central heating, so I thought I'd update it.

Our system was constantly losing about 0.5 bar after about 3 weeks or so. So a little more than 0.1 bar a week. After unsuccessfully trying to find any sign of leaks around the entire system I resorted to a single dose of Adeys MC4 Leak Sealer. I already had their MC1 protector in the system as it was.

The MC4 has fixed the problem for now. Pressure reduced by maybe 0.1 or 0.2 a few days after adding the sealer - probably just the air I inadvertently introduced through the Magnaclean working it's way back out again, as well as the MC4 finding it's way through the pipework - but after that the pressure has been rock solid steady for the past month. Sits at about 1.1 bar cold and gets up to 1.5 or so when all rads are on for a while.

These sealers work by fiddling with the surface tension of the system water, so I imagine that they can only work when you are talking about tiny weeping leaks and very slow pressure loss such as we had. We have a 10 rad system with about 100+ litres in it. I guess we were losing between 1 and 2 litres a week at most. I don't think a leak involving much more than this will be fixed by a sealer. So I wouldn't be surprised that anyone who has had a negative experience with sealers, probably were trying to seal a leak that was simply too big to start with....

Nonetheless, my experience with the Leak Sealer was a happy one. It has proven to be a massive headache saver. For the moment at least.

Mizuno Man · 17-01-2017 8:11pm

Oh and one or two comments I read about the unknown interaction between a sealer and a protector that is already in the system kind of made me laugh. Any company that makes sealer are expecting whatever system it is used in to have a protector in there already. I checked with Adey myself and they specifically said both that the inhibitor doesn't interact with the sealer and also that the sealer must be left in the system permanently.

Although I would imagine using a sealer from the same company and range that made your inhibitor would be a good idea.

Just for what it's worth.....

mrcheez · 18-01-2017 12:14pm

The Fernox F4 stuff worked exceedingly well on my setup. No leaks since 2014 *knocks on timber*

Central heating leak sealer

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