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Best Heating System Cover?
craig1410 - 19/12/07 at 12:50 AM

Hi Guys,
Both my neighbours have had their unvented hot water system tanks burst in the last 6 months and I feel compelled to buy some sort of cover in case it happens to me. We all have the same type of system in the same type of house and the failures so far have happened in order of commissioning with mine being third in line...

So, what company would you recommend for heating and plumbing cover (including water tank of course)?

British Gas?
Scottish Hydro?
Cover Heat?
Gas Sure?
Other?

Opinions and experience most certainly welcome!
Thanks,
Craig.

billynomates - 19/12/07 at 07:49 AM

Just ask your neighbours what caused the failure, and rectify that.
Personally, I wouldn't bother with any sort of insurance cover that isn't necessary, just save a few quid each month in case of an emergency, and then if there isn't one, you still have your money.

bonzoronnie - 19/12/07 at 08:42 AM

I would have it checked out ASAP.

Too much of a coincedence for my liking.

Ronnie

craig1410 - 19/12/07 at 08:44 AM

Easier said than done I'm afraid - both tanks failed due to not having had their sacrificial anodes replaced at the required intervals despite having a maintenance plan in place with British Gas. This allowed corrosion of the tank and subsequent failure. The chances are high that my tank has also not been maintained properly during the six years prior to me moving in so I fear it is only a matter of time before it fails. I don't fancy spending £1000 to replace the tank myself especially since I can't be sure that it is going to fail. The other two tanks might have failed due to poor handling during installation cracking the glass which is used to line the mild steel jacket. Mine could and should last for years to come.

Cheers,
Craig

Mr Whippy - 19/12/07 at 09:02 AM

Can’t you fit a vented tank instead (can't remember why folk fit the unvented systems), much safer. I got mine out of B&Q along with all the pipes & fittings, so easy to fit. Buy a plumbing book to see how to fit it or ask on here.

mild steel?! my tanks made of copper.

[Edited on 19/12/07 by Mr Whippy]

nitram38 - 19/12/07 at 09:07 AM

Most of these call out types like British gas are a con.
I installed my mums central heating in her bungalow and had the gas connected and checked by a corgi plumber.
I made sure that the Halstead boiler was supported by Southern gas etc, before buying.
They came out to do an inspection before the cover plan, condemmed the boiler and tried to get my mum to buy a new boiler and move it next door from the bathroom to the kitchen (pipework only 2-3 feet away) for £3400 !
The whole heating system only cost £1200 to install.
I tackled British gas and they said the boiler was condemed as it was in a bathroom but would not say why.
I rang corgi who informed me that the boiler was not "electrically" safe as it could pose a shock hazard.
I suggested fitting a cupboard (only £50) around it and they said it would pass!
Back to Southern gas and after lots of arguing they finally let my mum take out the plan.
The story does not end there.
18 months later, my mum noticed the direct debit had stopped so she rang them to ask why.
She was told that here boiler was no longer approved by the gas board and so they dropped her without even a warning letter.

If I were you, get you system checked every year and make sure you have good house insurance.

MikeRJ - 19/12/07 at 09:08 AM

quote:
Originally posted by Mr Whippy
Can’t you fit a vented tank instead (can't remember why folk fit the unvented systems), much safer.


Because you have to have a cold water tank in the loft which isn't always convienient or possible (e.g. if you've had a loft conversion).

If the insides of these tanks are lines with glass, why do they need sacrificial anodes?

craig1410 - 19/12/07 at 09:45 AM

Hi,
The unvented system is great as it gives you pressurised hot water and avoids the need for cold water tank in the loft, thermostatic mixer taps or a shower pump. I couldn't go back to a crappy combi boiler or non-pressurised hot water after having the unvented system!!

Safety shouldn't be an issue either as it has several safety devices fitted to avoid any nasty explosions. A water leak is the worst you should expect to see and let's face it, this happens very commonly at this time of year with loft mounted cold water systems. The only real downside of unvented systems is that you can't work on them legally without an unvented certificate.

I agree in general that many of these insurances are a con which is why I'm asking for recommendations as to which is best. Many have a £1000 limit per incident which wouldn't cover the installation of a new tank as the 210 litre tank itself costs around £700 + vat.

One option is to replace the tank pro-actively and risk throwing out a perfectly good tank. The other option is to wait and see and risk coming home to a flooded house.

Decisions, decisions...

Craig.

Mr Whippy - 19/12/07 at 10:44 AM

quote:
Originally posted by MikeRJ
quote:
Originally posted by Mr Whippy
Can’t you fit a vented tank instead (can't remember why folk fit the unvented systems), much safer.


Because you have to have a cold water tank in the loft which isn't always convienient or possible (e.g. if you've had a loft conversion).

If the insides of these tanks are lines with glass, why do they need sacrificial anodes?


hmm I see, all sounds quite dangerous, rusting pressure vessels, nice

nitram38 - 19/12/07 at 12:10 PM

As far as I am aware, a pressure vessel has an internal air filled bladder that presses against the water to keep the pressure steady.
The worst that can happen is the bladder giving up.

craig1410 - 19/12/07 at 12:14 PM

On my type of cylinder (Santon) it is a mild steel vessel with a glass lining to keep the water from contacting the steel under normal circumstances but with a sacrificial anode to preserve the steel in the event the glass lining is compromised. There is a separate expansion tank which is fitted with a rubber diaphragm and this is used to handle the volume change during heating and colling cycles. Some other types of cylinder maintain an air bubble above the water level in the main tank and have a baffle float to avoid the water absorbing the air bubble.

Cheers,
Craig.

martyn_16v - 19/12/07 at 06:04 PM

I've had no problems at all with British Gas. I was quite surprised when they turned up for the initial visit an gave my ancient combi the OK though. Since then we've called them out several times as the thing dies a slow death and they've fixed it with no extra charges every time. I'm well up on what it'd have cost me to get a CORGI bloke in each time without them

MkIndy7 - 19/12/07 at 08:08 PM

I wouldn't bother with the Heating system cover, as said it probably isisn't that comprehensive and I would have thought your house insurance would cover a mojor flood should it burst.

But I would get it changed pronto, I don't believe that they would be £1000 (nearer the £300 mark as you need only the vecylinder itself, no Exp vessels, pressure reducing valves etc)and its a pretty much DIY job if you get exactly the same cylinder again, If you have the skills build a car you can change that Cylinder!.

As you've said it sounds like your on borrowed time with the existing one, but if you replaced it and kept upto the maintainace schedule and checked the Annode then you should have no problems with a new one or the system as a whole.

craig1410 - 20/12/07 at 12:25 AM

quote:
Originally posted by MkIndy7
I wouldn't bother with the Heating system cover, as said it probably isisn't that comprehensive and I would have thought your house insurance would cover a mojor flood should it burst.

But I would get it changed pronto, I don't believe that they would be £1000 (nearer the £300 mark as you need only the vecylinder itself, no Exp vessels, pressure reducing valves etc)and its a pretty much DIY job if you get exactly the same cylinder again, If you have the skills build a car you can change that Cylinder!.

As you've said it sounds like your on borrowed time with the existing one, but if you replaced it and kept upto the maintainace schedule and checked the Annode then you should have no problems with a new one or the system as a whole.


Thanks for your advice - I've checked prices online and the closest match from Santon themselves costs something like £550 for the cylinder alone. I was assuming that I would need to pay £200 or so to get the cylinder changed over as the pipework would need some rework to accommodate the new cylinder layout. I don't think it's possible to get the same tank as is already fitted as they have been discontinued. Also, I wouldn't want one with a replaceable anode next time as there is insufficient headroom to remove and replace it (only about 9 inches). I can't even gain enough headroom by cutting a hole in the ceiling due to the roofline being low above the tank. Ideally I would want a 25 year guaranteed stainless steel tank which is anode free.

As for the DIY side of things, what exactly is allowed and what isn't? I thought that you needed an unvented qualification to work on these systems - is that not true? Are there some things you can do and perhaps some bits that you can't? I'm aware of the requirements of the discharge pipework and things like that which do require some knowledge of building regs but is a householder allowed to replace an existing tank when all pipework is already in place and just requires some rework to suit the new tank connections?

Cheers,
Craig.

MkIndy7 - 20/12/07 at 07:13 PM

If you left all the existing pressure reducing valve, check valves, expansion vessels, safety valve, and electronic valves and controls etc as they are and only altered the pipework after them to the heater I can't see any problems or why it would be specialist as its already been done to spec.

If there is no longer a direct replacement from santon then any make could be made to fit, if somebody makes one cheeper, I've seen them for around the £300 mark on Ebay.

For example:
http://cgi.ebay.co.uk/VAILLANT-UNISTOR-UNVENTED-HOT-WATER-CYLINDER-120LTR-NEW_W0QQitemZ130183241177QQihZ003QQcategoryZ105993QQssPageNameZWDVWQQrdZ1QQc mdZViewItem


There is also another method of protection that is used inplace of the sacrifitial annode called a "correx" system that works electrically to prevent corrosion. I'd guess that it keeps the particals that attack the vessel suspended in the water or makes it so there repeld from the cylinder walls.

This looks like a universal version of a Correx unit:
http://www.maplin.co.uk/Module.aspx?TabID=1&ModuleNo=37766&doy=20m12

The water must be very harsh on them where you live, In leeds an Annode in commercial use (office/shop) will last i'd say 3-4 years, yet in York you'd be lucky if it lasted 2!. I think its hardwater that does the most damage so it might be worth considering getting some kind of softner for the house as it will be accelerating the wear of you appliances etc.

I've no idea how effective these are but they might be worth looking into:
http://www.screwfix.com/search.do;jsessionid=0DAMRL4NHVIJ0CSTHZPCFFA?_dyncharset=UTF-8&fh_search=water+softner

[Edited on 20/12/07 by MkIndy7]

[Edited on 20/12/07 by MkIndy7]

craig1410 - 20/12/07 at 11:43 PM

quote:
Originally posted by MkIndy7
If you left all the existing pressure reducing valve, check valves, expansion vessels, safety valve, and electronic valves and controls etc as they are and only altered the pipework after them to the heater I can't see any problems or why it would be specialist as its already been done to spec.

If there is no longer a direct replacement from santon then any make could be made to fit, if somebody makes one cheeper, I've seen them for around the £300 mark on Ebay.

For example:
http://cgi.ebay.co.uk/VAILLANT-UNISTOR-UNVENTED-HOT-WATER-CYLINDER-120LTR-NEW_W0QQitemZ130183241177QQihZ003QQcategoryZ105993QQssPageNameZWDVWQQrdZ1QQc mdZViewItem


There is also another method of protection that is used inplace of the sacrifitial annode called a "correx" system that works electrically to prevent corrosion. I'd guess that it keeps the particals that attack the vessel suspended in the water or makes it so there repeld from the cylinder walls.

This looks like a universal version of a Correx unit:
http://www.maplin.co.uk/Module.aspx?TabID=1&ModuleNo=37766&doy=20m12

The water must be very harsh on them where you live, In leeds an Annode in commercial use (office/shop) will last i'd say 3-4 years, yet in York you'd be lucky if it lasted 2!. I think its hardwater that does the most damage so it might be worth considering getting some kind of softner for the house as it will be accelerating the wear of you appliances etc.

I've no idea how effective these are but they might be worth looking into:
http://www.screwfix.com/search.do;jsessionid=0DAMRL4NHVIJ0CSTHZPCFFA?_dyncharset=UTF-8&fh_search=water+softner

[Edited on 20/12/07 by MkIndy7]

[Edited on 20/12/07 by MkIndy7]


Hi,
I maybe should have mentioned, my tank is 210 litres hence it's a bit more expensive than the one you listed. I can get a very similar Santon tank with a 25 year warranty so that's probably what I'd go for. I'll have a good think about installing it myself since I agree with your thoughts that the "design" work has already been done. My only concern is whether it's been done correctly because I noticed that the installer hasn't filled in the details on the side of the tank as they should have done.

I don't think the water here in central scotland is particularly hard, in fact isn't scottish water normally quite soft? The anode has not been touched for 7+ years and the tank only has a 5 year warranty so maybe it has in fact reached end of life.

Thanks for the link to the correx system - very interesting - but I think if my tank is corroded then replacement is the only real option and a new tank would be stainless steel and wouldn't need a corrosion inhibitor.

I think I'll perform a basic service on the unit - check the filter, check the anode, activate the various safety valves and motorised valve and check the pressure in the expansion vessel is up to spec. That will give me a good idea how it all goes together and will let me see how good or bad the anode is. If it's in bad shape then I think a new cylinder is in order.

Thanks again,
Craig.

Ferg - 24/12/07 at 03:25 PM

Just a quickie.

You do indeed need Unvented Certification to comply with section G3 of the Building Regs.

I would imagine that this would only come to light should you sell the house (HIPS) or have a major failure thst brougt the HSE down on you.

craig1410 - 24/12/07 at 03:47 PM

quote:
Originally posted by Ferg
Just a quickie.

You do indeed need Unvented Certification to comply with section G3 of the Building Regs.

I would imagine that this would only come to light should you sell the house (HIPS) or have a major failure thst brougt the HSE down on you.


Hi,
Thanks for your message - it seems like a very grey area to me. I agree that G3 must be complied with (or its equivalent in Scotland) but as far as I can tell there is no firm requirement for the tradesman (or me) to have any sort of certification provided we conform to all the requirements. Assuming the installation conformed before the tank was replaced then as far as I can tell as long as I don't break any conformance as a result of my tank replacement then it should still be legal afterwards.

Different story if you don't have an unvented system installed in the first place where a building warrant is required and I the system must be inspected by a qualified unvented engineer afterwards.

Would you agree with what I have said here or do you know of some specific legislation that would prevent this approach? I don't want to break the law but I also don't want to be ripped off and/or have my tank burst. I can't afford a fully installed tank replacement but I might just manage a tank with DIY fitment which has to be better than just waiting for it to burst!

Cheers,
Craig.

Ferg - 26/12/07 at 05:02 PM

To be honest.....

I think we're going to find ourselves in the 'competency' situation.

HSE legislation (BS) will reqire work to be done by a competent person. The difficulty is how do you prove competency if anything should happen? I would imagine you could be cross examined in a court and if you couldn't answer all the questions regarding installation that might prove you 'incompetent'... If you have a CITB etc certificate to wave then it's their problem.

craig1410 - 26/12/07 at 05:38 PM

I see where you are coming from and don't worry, I'm not offended by your suggestion...

Surely to face court proceedings, I would have had to have made an error and this error would have to have contributed to some sort of incident. If so, then I would have thought that even a certified installer would face such claims of negligence if they had done something similar. I don't think you can hide behind a certificate in such cases.

I do take your point though and will certainly bear this in mind. I might even have a word with our local building control office to see exactly what legislation needs to be complied with. I'll approach them on the basis of wanting to check what sort of credentials to look for in a plumbing contractor for unvented system work.

Thanks (and merry Christmas by the way!)
Craig.