Biasi 24s repeated gas valve failure.

Heyho74 · 23 Dec 2007

Hello chaps, this is my first post here - so go easy on me!

My Father has recently fitted a used Biasi 24s gas combi, which when initially installed, worked a treat.

A week or so later, it packed in - pump running, ignition audible etc, but no go. My father diagnosed the fault as a faulty gas solenoid, which I later confirmed by measuring the coil resistance - should be 3k ohms, and was open circuit.

Fortuitously, we found one brand new in box on ebay. Once fitted, it was all up and running again, but alas a week or so later, the same thing occurred - open circuit on the lower coil of the gas inlet solenoid. The valve assembly is a honeywell VK4105M.

I've told my Father that the next step would be to find out the working voltage of the solenoid, and compare the actual voltage at the plug, in case the signal should be pulse modulated and the control circuit is overloading the coil.

Having quizzed him about the installation, the only thing not present is the inlet air restrictor in the co-axial flue assembly - could this have any bearing at all on the operation of the valve?

Cheers, Paul.

Gasguru · 23 Dec 2007

The majority of used boilers on ebay are in fact illegal to sell (since they do not come with all the relevant installation parts/instructions) and illegal to install since they don't meet current building regulations.

You appear to have installed a non-condensing boiler contravening building regulations.

Is this boiler fitted in his own house and is he competent/qualified? otherwise this contravenes gas safety regulations.

A gas valve has been replaced - were the tightness tests/sniffer leak tests/burner pressures checked?

Was the installation notified to building control?

Due to the low cost of the Biasi 24S they tended to be installed by cowboys and poorly maintained therfore a secondhand one is normally only of scrap value due to the abuse they have suffered.

My advice is have a new boiler installed legally.

Heyho74 · 23 Dec 2007

Thanks for the reply Gasguru,

To be honest, that is the response I was expecting.

I/we are fully aware of the situation regarding building control, and the fact that it is a non-condensing boiler. The boiler is fitted in his own house, and although he is not qualified in the sense you are implying, he is a competent mechanical engineer/toolmaker. The installation was "looked at" unofficially by a corgi registered family member before firing up (who lives in Aberdeen, so we cannot really call upon him now).

It's almost uncanny - your advice is exactly the same as that which he received from my Mother!

Gasguru · 23 Dec 2007

I had a customer that installed his own boiler about 15 or 20 years ago.

I went to investigate a serious gas leak reported by his tenants (now occupying his former home).

I found he had installed the copper heating pipework in close proximity to the pilot gas bundy tubing (actually touching in several places). Water had leaked from his poor and botched installation of the air seperator (non-manipulative compression fittings on soft temper tubing) above the boiler.

Electrolytic corrosion had caused a major failure of the bundy tube (5mm diameter) resulting in a significant gas leak when the timeclock attempted to fire up the boiler. It was only luck the tenants came home early before the gas concentraion had built up.

When (in his presence) I commented how poor the installation was and how luccky the outcome had been he confessed to the installation and then preceeded to tell me he was competent since his occupation throughout most of his career had been aircraft maintainance.

Electrolytic (or galvanic) corrosion is surely one of the most serious problems to be aware of in aircraft maintainance....but not to him.

Slugbabydotcom · 23 Dec 2007

Heyho74 said:
the only thing not present is the inlet air restrictor in the co-axial flue assembly - could this have any bearing at all on the operation of the valve?

Yes.

I do normally like to give more practical advice than that but this is potentially a can of worms.

FITTING SECOND HAND KIT IS BAD! mmkay Don't do it!

Have a look at THIS if money is the problem. You might be able to get a grant.

scatmanjohn · 23 Dec 2007

When (in his presence) I commented how poor the installation was and how luccky the outcome had been he confessed to the installation

At least he admitted it, most of em deny all knowledge.

When i ask "have you been dabling with this sir"

I usually get "no i have not touched it, honest"

bengasman · 23 Dec 2007

Mmmh, second hand boiler, was not worth much when brand new, wrong model, illegally and probably incorrectly fitted,.
Then it failed, and was repaired with an unverified part from fleabay.
The most practical advise I can give: if you want to kill people, use a gun, not a boiler.

Agile · 24 Dec 2007

Just for the record the 24S did not need any flue inlet restrictor!

It was only needed for the 28S.

In any case that would have no effect on the gas valve although it would cause the fan to overheat.

Its probably coincidental that the original gas valve solenoid failed.

Also perhaps coincidental that the replacement failed although from Ebay it might have been several years old and therefore failed prematurely.

Just this evening I was watching again an air disaster reconstruction where an aircraft engineer replaced a windscreen on a BAC 111 using the same size screws!

They were undersized and the eventual failure of the glass caused the captain to be sucked out of the plane. He was held by the legs by the copilot who was relieved by the steward and then safely landed the plane. The pilot survived and is still flying!

All because the aircraft engineer did not check the MI or use approved parts !!! Nearly killed all on board!

Same with unqualified gas boiler installation and repairs! Its risky!

Tony

Heyho74 · 24 Dec 2007

Thanks guys for all of the input.

Both myself and my Father are well aware of the potential dangers of DIY gas installation and repair - I will further reinforce all of your comments when I see him later today.

Hopefully he will see sense and opt for new.

Many thanks, Paul.

Agile · 24 Dec 2007

The 24S is a very reliable boiler when correctly installed on a clean system. There are probably nearly half a million in use in the UK.

IF its properly fitted then the advice would be to repair it by replacing the gas valve.

Obviously, I can only say that the valve should be fitted by a gas competent person !

Tony

wishiwascorgi · 24 Dec 2007

I attended a biasi boiler and it was dead. The diagnosis was reading as ready but no heat or hot water, it wouldn't even start. I took the switch off the divertor valve and manually pressed the switch and hey presto the boiler fired up fine. I stripped the diverter down and changed the diaphram and now it works fine. This was on the garda silver he 30. on the 24 it should be black. try removing it then depress the switch to try.

Also as stated before buying a 2nd hand boiler is not the way to have a long and healthy life. You have been sold something that is illegal and you should have asked yourself this question. Why did someone change this boiler. They were laughing at you when you bought it.

Agile · 25 Dec 2007

wishiwascorgi said:
I attended a biasi boiler and it was dead. The diagnosis was reading as ready but no heat or hot water, it wouldn't even start. I took the switch off the divertor valve and manually pressed the switch and hey presto the boiler fired up fine. I stripped the diverter down and changed the diaphram and now it works fine. This was on the garda silver he 30. on the 24 it should be black. try removing it then depress the switch to try.

You are talking about a later boiler!

They made them in 24kW, 28kW and 32kW but not 30 kW !

The switch you removed was the system flow switch!

Tony

Heyho74 · 25 Dec 2007

wishiwascorgi said:
Why did someone change this boiler. They were laughing at you when you bought it.

They weren't laughing at me, nor were they laughing at my father.

The Vendor had purchased the boiler, having witnessed it working, and for the many reasons already discussed in this thread, he was unable to find anybody willing to install it. As a result, my Father paid next to nothing for it - probably less than scrap value. I did tell him at the time to forget it, and get a new one.

Thanks Tony for the extra info. As already stated, the installation has been verified as good by a corgi badge holder, so I'll see if he'll get it repaired "officially", or replaced.

All replies much appreciated.

Agile · 25 Dec 2007

They are very reliable boilers when fitted on a clean system.

Now its fitted, although a bad thing to have done, its cheaper and better to have it repaired.

As a matter of interest what year of manufacture is it? Last four digits of serial number!

Tony

Heyho74 · 25 Dec 2007

Not sure of the SN, but pretty sure it says year of manufacture 2000 on the printed label.

diynot

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local

Biasi 24s repeated gas valve failure.

Similar threads