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Tundish leaking water.... advice sought

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J

Jonna

Hi All,

First post...

I bought a new Bellway house last year and have had a few probs with it since moving in. After around 4 months (December 2010) I noticed damp in the kitchen ceiling below the cylinder. On inspection the water (cold) appeared to be leaking from the tundish, which tuned out to be the result of a frozen blow-off waste pipe outside. The plumber stopped the leak (no idea what work was carried out), and added lagging and a cover to the external pipe.

On Sunday, I noticed water dripping from the ceiling again in the kitchen... same issue as before, water appears to have been leaking from the tundish. No blockage in the external blow-off drain however, in fact there are signs that a large amount of water has been draining outside. Plumber came, but suggested he'd need to take the ceiling out in the kitchen to locate a fault in the blow-off drain - he advised he'd have to come back later.

Came in tonight and noticed more water in the ceiling and more outside. There's also evidence that water has been overflowing from the tundish...

I'm waiting for a call back from Bellway regarding the plumber, but was hoping you guys could clarify...

1. Why the tundish? This thing doesn't appear to be capable of managing a heavy flow of water, and when a heavy flow (i suspect) does ensue, water pours out, down the outside of the pipe onto my kitchen ceiling.

2. Any ideas what would cause a constant dripping of cold water through the tundish? (faulty blow-off valve perhaps, or too high pressure in the system?)

Thanks. :cry_smile:
 
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An unvented system should not be spilling water from tundish if properly designed/installed by a competent fitter. This immediately sound alarm bells. These system are dangerous if incorrectly installed. My advice would be switch it off and have a qualified Engineer with his unvented qualification look at it.
 
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Images below - thanks for the prompt replies fellas.

There are three feeds running to the tundish (two visible in the pic, lower hot, upper appears cold) and a third running to the pressurised vessel above the cylinder.

Ignore the white band below the openings on the tundish - this is just a folded piece of bog roll I taped on temporarily last night to determine if the tundish itself is spilling water. This was soaked when I got in from work tonight, so I assume it 'is' spilling water.

Looking through the opening on the tundish, water often appears to be dripping slowly, though not always... that said, I'm convinced that on occassions, large quantities of water are p!ssing out of this thing.

As mentioned earlier, I'm still waiting on another visit from the plumber in the next day or so...

cylinderplumbing.jpgtundish.jpg
 
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Thanks for pics

The discharge pipework and tundish is undersized,maybe leaking out from tundish as upper rim scaled as been leaking through a while,need to get a qualified plumber in to trace which safety valve is leaking,why,correct problem ,check installation ok and run correct sized discharge pipework

imho
 
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Jonna said:
Hmm... perhaps the pics will help. I simply can't see how this thing could possibly cope with a large flow of water?
Click to expand...
Thats just it Jonna. The tundish should be able to cope with a run of 95°C water at high pressure flowing out. Otherwise it is dangerous. Simple as that. As per my last post. Turn it off and have a suitably qualified person look at it as soon as.
 
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stani said:
Puddle, how can you tell the discharge is undersized from the pics, without knowing how far, bends etc?
Click to expand...

well dear watson

coz the 2 15mm size pipework should tee into at least 22mm however op saying another pipe also maybe,but the two we can see mean tee into 22mm pipe and tundish bottom of which should be 28,which infact the 22mm reduces up to 28mm before going into floor
 
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Firstly why is there a flexible hose connecting the 2 safety valves to gather this is a no no should be teed on to 15mm copper in copper
Second I have used they type of tun-dish before and they can and do spay out if safety valve open fully

We can't say the discharge pipe is undersized As we can't see the length how many pulled bends or solder bends but however it is strange to reduce up if only 22mm needed and as a 15mm to 22mm tun-dish comes as standard to these cylinders it does look like the installer was to lazy to get a correctly sized tun-dish

But the biggest problem is why is there water being discharged in to tun-dish it could be either the expansion vessel is not pressurised or diagram split
Cylinder over heating or just a faulty safety valve

The third 15mm pipe is coming from the heating side safety valve probably from valve that comes with expansion vessel kit
Probably not ideal but I don't really see this as a problem but personally I'd of upgraded pipe to 22mm as said by puddle
 
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puddle said:
well dear watson

coz the 2 15mm size pipework should tee into at least 22mm however op saying another pipe also maybe,but the two we can see mean tee into 22mm pipe and tundish bottom of which should be 28,which infact the 22mm reduces up to 28mm before going into floor
Click to expand...

the 2 15mm (D1) should go into a tundish with an outlet at least 1 size bigger, which this does. they dont need to tee into a 22mm and then into the tundish, that is not whats required.
 
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stani said:
the 2 15mm (D1) should go into a tundish with an outlet at least 1 size bigger, which this does. they dont need to tee into a 22mm and then into the tundish, that is not whats required.
Click to expand...

Yes you are correct but as there is 3 would not hurt and as any tun-dishes I have ever got are 15mm to 22mm
Or 22mm to 28mm
So not really a problem
 
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stani said:
the 2 15mm (D1) should go into a tundish with an outlet at least 1 size bigger, which this does. they dont need to tee into a 22mm and then into the tundish, that is not whats required.
Click to expand...

how can you have two 15mm pipes discharging at full rate into a 15mm (ie same size pipe)without causing sever restriction to one or tuther or both thus altering set discharge rate on one or more safety valves,not a good idea and then we have a third :sad_smile:

imho
 
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The flexi is a standard on the OSO, well the ones I've seen anyway, and I don't agree with it as well, like you said should be copper.

With the extra 15mm going in, as said prob from htg prv, I would have increased d1 to 22mm before tundish and then used 22 - 28 tundish, must be a complicated or long discharge.

Must admit though that I haven't seen a discharging tundish that doesn't put water everywhere, even when everything is 100% to regs. Especially like it when the tundish is right next door to immersion fused spur. :)

As Gray0689 has said though needs pressure vessel and other safety devices checking out.

Make sure the plumber that comes out has his g3.
 
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MI's the holy grail of information, both 15mm's tee together and then into the tundish as supplied, 15mm x 22mm, and are'nt the operating pressures of the T&P and the PRV different so we would not have the situation of both discharging together.
 
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stani said:
MI's the holy grail of information, both 15mm's tee together and then into the tundish as supplied, 15mm x 22mm, and are'nt the operating pressures of the T&P and the PRV different so we would not have the situation of both discharging together.
Click to expand...

Icoming mains pressure above 7 bar, pressure reducing valve fails, both 'probably' would blow off. 7 bar isn't even that high round these parts, highest I've come across was just under 12 bar on an incoming main. Forget the pressure washer :) :)
 
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