Cast Iron central heating in a church, should we upgrade?

[James S]

Hi All, I'm after a bit of advice about our church heating.
We have a cast iron central heating system in the main church building that has recently suffered a leak where it joins onto the newer (circa 10 years old) boiler feed steel pipework. Finding a contractor who wants to work with cast iron was interesting! The radiators themselves appear ok, with most of the pipework between radiators seeming to be ok, though the valves are a bit worse for wear, some weeping slightly from the valve stem.
My question is, do we replace the whole system, or keep the radiators and just replace the pipework? Getting modern radiators to give the same output as these 2m wide 1.5m high monstrosities would require massive modern radiators I expect.
Any advice would be greatly appreciated.

 

[ShaunCorbs]

Unfortunately replacing would be best part of 100k depending on size

as for finding someone best to find someone who does commercial repairs

as for valves leaking they may want a nip up on the packings or rebuilding

 

[siricosm]

I would keep the cast iron radiators because I think they look pretty. They also have a large thermal mass, which can be advantageous.

Are the pipes really cast iron? New and old steel pipes can look different because the new are often galvanized and look silvery, and the older ones are black. If they are both steel, then I don't see why a good connection cannot be made. Can you please post a pic of the pipe connection between new and old where they are leaking?

If they are really cast, I have no experience with that kind of pipe.

The leaky stems on the valves on the rads are easy to fix, you just loosen the little nuts off, wind some rope packing around, and re-tighten them.

 

[Knappers]

Sounds like a proper job!
Would be really hard to define the work needed to repair even after seeing and imagine most would push towards replacement.
Have you looked into warm air or radiant heating?

 

[Gasmk1]

Most churches I worked in when updating used fan assisted rads

 

[James S]

Hi All, thanks for the replies.
I sent the post, then had a hectic few days! I'll get some photos of the area, but I'm now leaning towards leaving the original radiators.
The pipework that leaked had split at the connection between the original cast iron, and the newer steel pipework when the old oil boiler in the basement was replaced with the gas fired combi boilers in a new boiler house. After talking to some of the older members, this was all done around 25 years ago (I was 11, so only vaguely remember it) so the boilers are getting on a bit.
It doesn't sound like there's a great risk to the radiators/pipework failing further, but with the boilers being that old, i think we might be best using the money we do have to replace the boilers instead.
We have a budget of around £25k, which doesn't sound adequate to replace the whole system!
I think I'll recommend the boilers for now, and get a quote to replace the current radiators with the fan assisted rads a few have suggested. Then we'll know how much we need to have saved up in order to carry out the works on one go.

 

[ShaunCorbs]

I would get some pics first then we can advise as much as you can eg boilers pipe work, where the split etc

 

[James S]

I took some photos of the system today. Firstly the boiler house. There is 1 x Vokera 28 SE Mynute, which I think was replaced in 2005, and 2 x Vokera Linea 28 that were installed new in 1998. The running time on the Mynute is 1319hrs, and the Linea's are 12257hrs and 6689hrs. There's a Heatmiser control that's supposed to share the hours, but it isn't working too well between the two Lineas!



All 3 boilers are linked to a low loss header, then there's a pump that serves the back hall, corridor, toilets and creche room. That has been previous upgraded to 1 inch steel pipework, and modern rads about 8 years ago.



The other pump serves the main church and the front porch, which is all still original cast iron pipework and rads. I think the pipework is 3 inch, but the pipes leaving the low loss header are only 1 inch, so not ideal I don't think.

This is where the cast iron elbow cracked, and has now been replaced with a steel fitting.

This is an example of one of the leaking valves, only 4 out of the 15 rads are leaking, with this one being the worst.


This is an example of the 8 radiators in the main church, i hadn't realised they were up on legs, so not as big as I thought, 1m tall by 1.2m wide.


The pipework leaves the boiler house and goes down into the old underground boiler house, then enters the left side of the church and leaves the right side, at that elbow, or it might be the other way round, not sure!



Sorry for the large post, but any advice would be greatly appreciated in how best to protect the system, without spending more than around £25k.

Thank you!

 

[ShaunCorbs]

Standard steel pipe system any commercial engineer should be able to sort this make sure they have done steel pipe work before cutting and threading

Agree boilers need changing and re doing as that high boiler isn’t good as it’s too high

The leaky rad valves just need there packing gland tightening and the rust removing and painting (don’t keep opening and shutting these valves there not meant for this)

The rad that is on legs it’s been piped up as it’s on a one pipe system for some reason this need investigation too see if the others are piped in the same

 

[Knappers]

Would be nice to maintain the pipework and rads to keep original.
You've got 3 boilers cycling so can swap them out when you like?
The big issue here I think is going to be 'too many fingers in the pot'.
Find a good firm that isn't desperate to convert your 1 pipe and peper the system with bits of copper and hold on to them!

 

[Last Plumber]

It's just an old one pipe system (with an alteration to two pipe in places it seems). As @ShaunCorbs said, any Plumber with experience in commercial heating should be able to fettle your problems. They don't look much from here to be honest. Not a bad job!
I would also agree with @Knappers advice on using a good firm who appreciate the work that needs doing and want to do it properly. I would keep your ideas about spending a lot of money quiet for now and find the right Engineer with eyes/hands on advice.
The plant room pipe work leaves a lot to be desired and a pair of Vaillant boilers and a plate heat exchanger would look good eventually.

 

[James S]

Thanks for the replies all, much appreciated.

There certainly has been 'too many fingers in the pot' in the past! We have recently formed a buildings committee, and my background in industrial maintenance and now electrical engineering has given me the responsibility of mechanical and electrical items! Just not done much at all with heating on this scale before. Small domestic, and huge industrial yes, but nothing inbetween!

I'll look for a good local firm for some advice, making sure they're not just in it for the money.

That was going to be one of my next questions, which make of boiler would you all recommend? I have read very good things about Viessmann (considering one to replace my 35 year old council installed back boiler this summer) but would you recommend Vaillant over them?

 

[gmartine]

Not for me James S, there are some Vaillant models with a stainless steel hex the Eco Tec Pro I think off the top of my head but they mainly use aluminium. Do a search on here and you'll find we all have our favourites, I think a Viessmann is worth paying the premium for albeit they do have models that span across the price range now you do have to pay to extend warranties to around 10 yrs where other manufacturer's are issuing them for free. The 200w has a huge modulation range which is class leading which means it can tick along at a couple of kw when it's not so cold or you have a smaller property without it say short cycling BUT it's comparatively very expensive.

 

[ShaunCorbs]

Viessmann 200 or Worcester’s 162s

If you choose vaillant you need someone who specialises in there controls system as there not easy to set up but once they are there good

 

[gmartine]

@SC, for his own place I think not the church.

 

[James S]

@SC, for his own place I think not the church.

No it was both!
I'm pretty set on the veissmann at my house, but was curious on thoughts for the church as well.

 

[Last Plumber]

No it was both!
I'm pretty set on the veissmann at my house, but was curious on thoughts for the church as well.

Well if you ask on here or any other forum, you'll get a thousand opinions. There is no right or wrong answer as they tend to be based on personal preference (which is based on experience hopefully). It is a bit like asking what car should I buy.
I would recommend you find the worthy Engineer first and take their advice, as it will likely be them that look after it over the years to come.
With your type of system (Church) you do need the advice of an experienced person. The all singing and dancing highly efficient controls we use today are good but if they are controlling an old one pipe system that was designed many moons ago they can be unnecessary. Sometimes simple is best.

 

[WC1]

You'll get a bit more heat out of the rads if you remove the shelf over them, heat rising and all that.
While you're thinking of such things, have you looked at insulation, draught proofing etc?

 

[James S]

You'll get a bit more heat out of the rads if you remove the shelf over them, heat rising and all that.
While you're thinking of such things, have you looked at insulation, draught proofing etc?

I'd never thought about removing the shelves before! Good idea, I'll suggest it.

Were good with draft proofing, mainly from the Windows, which were replaced with UPVC a year or so ago.

Insulation is pretty minimal, if any to be honest. Nobody has been up in that section of ceiling/roof for quite a while, it's very hard to access! Another good suggestion though, thanks.