netaheat electronics case test

[dancraig]

Hi guys,

having some issues with numerous people about tests im carrying out.50% of people agreeing with me 50% disagreeing.

I was servicing a netaheat electronic and could hear a 'whistling' noise when the boiler lit.Carried out a match test and an analyser around the case and back of boiler,removed case and checked backplate,obviously,but nothing was showing.Then i checked the flue seal,where the flue box bolts to the back of the boiler, with ldf and saw a bubbling around the seal when the fan was running, i turned the boiler off and bubbling stopped.Disconnected blr as i.d and have been doing the same ever since.

I have been told that this is not an 'approved' test but i am not convinced.Gas safe and numerous commendable technicians agree with me, some other people who say this doesn't agree with there 'operational procedures' seem to disagree and as long as you carry out suitable analyser checks boiler can be left on.

I phoned pottertons twice, the first time they agreed and said ldf was a recognised test and boiler should be i.d.When i asked for it in writing he said 'email us and we will reply with confirmation' which never materialised.Second time they disagreed and said the only recognised test was a match test.Even analyser test wasn't suitable apparently.

So mixed opinions all round, i'm curious to see everyones feedback from here

Cheers

Dan

 

[kirkgas]

i havent heard of using ldf for this but surely if it showing a leak then it is the way to do it, we are always banging on about safety so i would say you are doing your bit for safety

 

[dancraig]

I agree 100%.I never heard of using ldf either until the issues with the rubber vaillant seals a couple of years ago.I was advised when replacing with a graphite seal that to test it you a)test around door seal with ldf and check for bubbling b) refit combustion case and performance test.

 

[Toddyplumb]

Neta heat is ASBESTOS seals !!!!

 

[dancraig]

whats your point? Doesnt matter it its asbestos,if its leaking its leaking!!!!!

 

[Bartdude]

You need one of these to test for leaks on a boiler casing

Toolstation > Plumbing > Testing & Reporting > Smoke-Pen

This was part of my practical test the last time I went through my CCN 1

 

[Toddyplumb]

It wasnt a point it was a warning.

 

[dancraig]

sorry i misunderstood, yeah i know they are asbestos.Another reason why i explain to customers that the boiler needs replacing if seal is leaking.Customer said to me yesterday 'this boiler has been going for thirty years, if we change that seal theres no reason why it won't go another thirty years'

 

[Toddyplumb]

I know exactly what you mean

 

[dancraig]

If the boiler was on the front of their house next to the shiny new car i guarantee they would have a new one very five years

 

[GrahamM]

You need one of these to test for leaks on a boiler casing

Toolstation > Plumbing > Testing & Reporting > Smoke-Pen

This was part of my practical test the last time I went through my CCN 1

Me to. Gives a very clear indication, but not cheap though.

As far as I recall. A smoke test is only approved method of testing.

Just a though, could the seal being soaked in LDF affect its integrity and show a leak?😕 It would not normally be wet and this is not an approved method of testing after all.

 

[Reg Man]

The case seals on positive pressure boilers are highly unlikely to pass a seal chech with LDF even when they were new. The only sure way of checking is visual and ambient co reading in the room above the boiler. Also a clear indication of a problem is poor combustion from the flue. Theory being that if the case seal or back plate has been impaired then the fan cannot now push enough air through the appliance because its loosing pressure through the gap and then causing vitiatation to the secondary air on the burner. High CO and a nice hole for it to pass through.

Fortunately they are becoming easier to condem, as the years go on. Always recommend CO Alarm, if I have to pass one.

 

[dancraig]

The only issue i have with this is potterton and gas safe have told me that ldf is a suitable method and if there is any bubbling around any seals it is i.d.i quote 'no ifs, no buts the boiler must be disconnected'.First time i spoke to potterton they agreed but when i phoned back and got someone else he said 'ldf isnt approved but if there is bubbling then it is definitely i.d' so he has contradicted himself. We all know that the cases would never seal 100% as you allow a 5% spillage, but how do you measure the 5%? If you know there is any chance that a positive pressure blr is not sealed in any way, shape or form in my opinion it is i.d and when i find any more they will be going off.There has been too many co incidents for me to take any chances with these boilers

 

[prs1]

The problem i see with this is that somme seals can absorbe moisture and swell and that could render a leak undetectable and as said seals are not normally wet in operation!Also a slight leak could be sealed with LDF.
Although its very admirable that you are being so thourough in your testing.

MI's rule.

 

[GrahamM]

The fact that Potterton is giving mixed messages on this issue says it all. In this instance they are not sure themselves.
LDF is a medium for checking leaking joints and test points. It is not an approved medium for testing case seals. In the same way testing for a gas leak with a match is not an approved method, but I am sure it would work.
Stick to the approved method and you will be working safely and competently. The smoke pen gives a very good and clear indication of the slightest leak and if still not convinced use a FGA round the seal and above the boiler.