Corroding Boilermate - replacement?

[Fishboy]

Hi,

I recently moved into a house of around 15yrs old that was fitted with a thermal storage system from new. Unfortunately the Gledhill Boilermate part of this is corroding a bit where the expansion tank and main unit join (its the base of the expansion tank thats leaking). I'll probably have to get a plumber to look at it but has anyone had similar problems and if so did it require replacement with a similar unit or did would I be better to change the system to a combi-boiler or other? It would also mean I could shift this to the attached garage.

Thanks,

Andy.

 

[croydoncorgi]

If its leaking at that joint, chances are heatstore is dead meat!

Not really worth considering replacing like-with-like. Firstly, the heatstore operates at 80 degrees or so. This means it's fundamentally incompatible with a condensing boiler (the Return temperature to the boiler will be far too high most of the time, so it will never condense!

If you DO decide that a combi is the right way to go, be careful what you wish for! A heatstore gives you (in effect) unlimited hot water because the water is heated as it is used but the actual heat comes from a VERY big store. A combi uses the same approach but there the heat source is limited to the power of the boiler (say, 28 kilowatts). This can only deliver a certain volume of water per minute at a specified temperature. Make sure you get a boiler which will meet your expectations: for example, shower plus kitchen hot tap simultaneously means AT LEAST 30Kw. You might also look at storage combis, such as the Worcester Hiflow.

 

[Fishboy]

If its leaking at that joint, chances are heatstore is dead meat!

Wouldn't surprise me, shower goes from hot to warm after a couple of minutes. I'll try and figure out how to add a piccie..

Not really worth considering replacing like-with-like. Firstly, the heatstore operates at 80 degrees or so. This means it's fundamentally incompatible with a condensing boiler (the Return temperature to the boiler will be far too high most of the time, so it will never condense!

What would you suggest I replace it with? New to all this so I don't have a great understanding (any!) of the various options. Don't mind the principle of the thermal store if its efficient enough. Any advice very gratefully received!

Thanks for your help,

Andy.

 

[Fishboy]

Hopefully this will show the problem..!

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[pierrot]

8) sounds as if the gledhill may have reached the end of the road, we`ve recently pulled a load of gledhill cormorants and gulfstreams out of around a similar vintage, quite frankly they were becoming a nuisance with minor leaks and furred up heat ex`s. Also came across a few with corroded burner canopies.

 

[kevplumb]

have to be honest and admit ive never fitted a gulfstream but they look good on paper

 

[croydoncorgi]

From the pic - definitely Beyond Economic Repair.

Problem you have to face is as follows:

Your system (heatstore, boiler, etc. ) is designed around the heatstore.

Presumably the central heating flow connection (with a circulating pump) and return connection are onto the heatstore. So to install a Combi boiler, you would need to extend the CH pipework to wherever it is to be fitted, along with cold mains and hot water supply pipes. Probably quite a lot of work and cost.

But if you replace the heatstore it will NEVER work efficiently with a condensing boiler in the future (there's a basic design conflict between heatstores and condensers).

Your other options would be:
- repipe the CH so it comes straight off the boiler and install a conventional cylinder with a cold tank on top (still no decent hot water pressure!),
- as above but with an unvented HW cylinder (needs licensed plumber!).

On the face of it, the combi option is probably least worst case but still quite expensive.

 

[lor]

seems a waste to throw away the enter Boilermate just bcos the f&e is leaking.they r vexpensive.if u have enough pipe exposed u could remove the f&e and pipe a remote one on (appprox £15 for f&e + float valve)
Any rust damage to top of cylinder is only superficial as this is just a skin holding in the insulation.
good luck

 

[Fishboy]

Cheers guys, I'll need to get someone in regardless so we'll see what happens then. When you say it'll never work with a condensing boiler is that because any replacement boiler would have to be one of those. Presumably it would work with the existing boiler??
Thanks again,
Andy.

 

[bab]

is this a traditional thermal store with a remote boiler & if so why do they have "Burner canopies" dont see them around these parts cowboy.

 

[croydoncorgi]

I suppose that having a heatstore might be sufficient reason for NOT installing a condenser as a replacement boiler and getting a conventional one instead. I've never actually been asked this before!

There's a formula for determining whether a condenser is mandatory, giving a number of 'points' where each point is roughly equivalent to £1 of extra cost. If the points total more than 1000 you can stay 'conventional'. Unfortunately, having an existing heatstore does not give you any points at all as far as I can see (http://www.odpm.gov.uk/index.asp?id=1131465#TopOfPage).

There should be no problem with getting a new heatstore to work with the old boiler, so long as the latter remains serviceable.

 

[Fishboy]

Yeap, remote boiler but no idea what a "burner canopy" is!

Thanks for the ODPM link CC, I hadn't appreciated why the condensing boiler bit was so critical. Also, the ticker tape here http://www.nef.org.uk/energyadvice/boilers.htm says that these are mandatory from 1/1/2006 onwards. If there are no exceptions to this then like you said there is no point in spending a ton on a heat store because if I then have to replace the boiler I'll have to do all sorts of changes anyway. What a bummer!!

Thanks again, you've been a great help,

Andy.

 

[Fishboy]

Jeez, the plot thickens, a replacement Gledhill thermal store would work with a Gledhill HE condensing boiler, should the boiler ever need replaced.

"The Gledhill HE Condensing Boiler is suitable for use with any double feed storage vessel but has been designed to work particularly well with a thermal store, such as the Gledhill BoilerMate A-Class, or an Accolade A-Class unvented cylinder."

Cheers, Andy.

 

[croydoncorgi]

I'd love to hear Gledhill's explanation as to how a heatstore designed to work at (say) 80 degrees can be made compatible with a condensing boiler which CANNOT condense (laws of physics) if the return temperature is MORE than 55 degrees.

Many people's arguments about the benefits of condensers are based on the assumption that they will do most of their condensing while warming up from cold and do not spend too much time at the temperature setpoint. A heatstore will be at a high-ish temperature ALL the time. otherwise it wouldn't work!

Repeat the following mantra: 'A condensing boiler without weather compensation and / or low-temperature radiators is an unhappy boiler!'

 

[Fishboy]

I just want a nice easy, cost-effective solution!