# Jerry Can in the Hot Press!



## Soarer (26 Oct 2010)

Hi all.

We're buying a new build house, and it has a solar system installed. What's worrying us though, is as part of the system, there's a Jerry Can in the hotpress, with a copper pipe feeding into it.

Now I don't know about plumbing or solar systems, but I'd have thought that a system like that shouldn't have to be depending on a can in the hotpress for any part of the system.

I asked the plumber about it, and he says it's there to catch the anti-freeze in case the valve goes. 

Does this make sense to anyone, or should I be worried?


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## PaddyBloggit (26 Oct 2010)

Get a survey done on it.


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## Soarer (26 Oct 2010)

Thanks Paddy.

Not to sound overly thick, but who would I get to do the survey? Surely a "normal" engineer won't know the ins and outs of a solar system?


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## PaddyBloggit (26 Oct 2010)

I don't see why they wouldn't.

My local plumber suddenly became an expert installer.

I'd ring a few and tell them what you expect of them. Aske them if they can do it and ask them how much.


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## villa 1 (26 Oct 2010)

The solar system should have a copper pipe attached to the relief valve and this pipe should be piped outside the house. This valve is fitted to relieve excessive pressure if the solar system overheats. This should not happen if a proper heat dump has been fitted. 
Most solar installers are/should be qualified plumbers and not engineers!! The celtic tiger introduced heating/solar engineers!!


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## Soarer (26 Oct 2010)

Thanks Villa.

There is a copper pipe going into the can from (what I can only assume is) the heatpump.
He said the reason for the can is two fold:
1. In the spec, it says to use a container to catch the antifreeze/coolant in case of the relief valve popping.
2. He said that if it was piped outside, someone could get scalded if they were near the pipe when the valve went.

Is that plausible?


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## villa 1 (26 Oct 2010)

If the relief valve pipe is to be piped to the outside it should be fitted near to ground level thus eliminating the risk of scalding and as said recently, the escape of hot water/antifreeze mix will rarely happen if a heat dump/radiator is incorporated into the solar insatallation.


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## clonboy (26 Oct 2010)

If the anti freeze should leak from the system the cam will trap it, there is a clear gallon can in mine .as it's clear I'll see any leaks, solar system won't hold anymore than a few litres


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## PaddyBloggit (26 Oct 2010)

Only way to be happy ... get an expert in who'll check it for you.


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## quentingargan (27 Oct 2010)

Soarer said:


> Thanks Villa.
> 
> There is a copper pipe going into the can from (what I can only assume is) the heatpump.
> He said the reason for the can is two fold:
> ...


The procedure you have is in this house is appropriate and quite common on solar installations. It is not permitted to send anti-freeze to a drain, so it is common to collect this in either
1) A metal container properly fixed in a location which would not be easily accessed as, in the event of the system exceeding working pressure, the steam going into this vessel would be hot
2) A plastic container with fluid in it which would ensure that the steam entering it would condense, and not cause the plastic to melt. 

There is another logical reason for doing this. If there is a drop in pressure in the system (which should occasionally be checked) then it is easier to diagnose the cause - if it is becuase of a pressure relief incident, there will be fluid in the can. If not, it is probably a leak. 

Please note that in practice, this should never happen, and if the installation is well done, that jerry can will remain empty and unused.


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## villa 1 (27 Oct 2010)

In my opinion the "metal Jerry can" should be fitted outside. This will collect any harmfull anti freeze solution should the system overpressurise, which as quentingargin says should not happen if it is installed properly.
Nothing more horrific than to see an open bucket in a hot press especially if a sock falls into it an start to rot and stink


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## quentingargan (27 Oct 2010)

Personally, I prefer to see this put in the loft. It would rust if left outside, and in any event, the EPA would not be impressed with any idea that propylene glycol antifreeze was being ditched into storm drains.  

There is also a custom desinged plastic bottle available, but it is about €100. 

But in terms of the initial question from Soarer, I wouldn't be worried about this and the explanation given is plausible and this solution is better than many I have seen, which usually involves putting the pipe into the original 10L glycol container at the bottom of the hotpress.


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## TripMeUp (27 Oct 2010)

Soarer 

As Quentin says, this is not uncommon and is nothing to worry about...


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## Soarer (27 Oct 2010)

Just checking back in now guys.

Thanks for all the info. It's good to know that the wool isn't being pulled over my eyes.


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## bertie1 (29 Oct 2010)

It is normall & will only operate if the high pressure valve goes off and it normally doesn't . You can not put it into a drain & having it in the hot press as opposed to the attic means you will actually notice if anything comes into that bucket , it will alert you something is wrong


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