Author Topic: Pool heater underground piping  (Read 344 times)

Offline enzof

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Pool heater underground piping
« on: June 21, 2020, 07:49:27 AM »
Looking for guidance running underground piping for a NG pool heater.
Does anyone have experience doing these installs? This will be my first one.
Here's my list of materials and installation notes:

1. 1 1/4" pipe from meter (250K BTUH pool heater 100ft from meter)
2. Chamfer and cutting tools for PE pipe
2. 2 metal risers
3. 2 insulated unions
4. 2 ball valves
5. Trace wire
6. 15lbs x 60min test pressure
7. Minimum 15" burial
8. Venting will be at a later date as the heater has not been selected.

Am I missing anything?
Any protection for piping?
Support for the metal risers?
Meter upgrade?
How is the electrical normally treated? Same trench, different depth?
I'm reading 12" apart vertically or horizontally
As a substitute, can I run CSST in a conduit?

Any help will be appreciated.

Offline Hgye

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Re: Pool heater underground piping
« Reply #1 on: June 21, 2020, 08:49:31 AM »
Here, we use the 7-14 chart, so we could use 1”. You will need swing joints. You will need the riser brackets to secure them.  Sand to backfill.  We would let Enbridge know we are adding an appliance, and they would decide if they need a meter upgrade. If you run csst, it would have to be rated for underground, conduit or not.  Poly is a lot more economical. We can run electrical in the same trench.

Offline enzof

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Re: Pool heater underground piping
« Reply #2 on: June 21, 2020, 08:56:02 AM »
Thanks for your reply.
Didn't think about the swing joint.
I'm in GTA (Toronto, Hamilton), where are yo located?
I thought we always use 7"WC

Offline Admin

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Re: Pool heater underground piping
« Reply #3 on: June 21, 2020, 11:28:57 AM »
Likely your supply pressure exceeds 7"wc and Table A.1 is 7"wc @ 0.5"wc pressure drop.

I use Table A.2 in Ottawa, 7-14"wc @ 1"WC pressure drop.

At least if you've been using Table A.1 you haven't been under sizing the gas pipe.

And yes, with dual party trenches I normally see the electrical buried at 24" and then covered in sand and then the gas line at 15".

I had not considered the swing joint.  Where do you find that requirement?

Offline Hgye

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Re: Pool heater underground piping
« Reply #4 on: June 22, 2020, 08:34:56 AM »
I had not considered the swing joint.  Where do you find that requirement?

6.16.3
You need to guard against settling. Enbridge will call us on it if it doesn’t have a swing joint.

Offline Porcupinepuffer

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Re: Pool heater underground piping
« Reply #5 on: June 27, 2020, 09:31:16 AM »

I had not considered the swing joint.  Where do you find that requirement?

It's definitely a requirement. Inspectors look for this every time with an underground run.
It's not in our code book (I can't understand why it wouldn't be included). It's either found in the installation instructions for underground piping, pool heater instructions, or enbridge has it in their set of guidelines.
You need to have a minimum 3 elbow swing joint. (Similar to how enbridge has a 3 elbow swing with their meter assembly). In many instances, you can't quite pipe it correctly for a 3 elbow swing, you may need to make it an even uglier 4 elbow swing.
It's all for frost movement. It needs to have these joints for movement of up/down side/side. Without it, a black iron fitting can snap clean off from excessive movement.

...You also need to use their special dielectric unions for the risers. If you really hardly ever do these installs, you don't need to invest in the chamfer tool. The pipe will slide into the risers without it but the tool does make it slip in a little nicer. You need to push the pipe in with all your might to make sure it's seated fully. Usually works a lot better with two guys. I usually secure a valley hanger on the riser to the wall, and then install the union and another piece of black iron with another valley hanger. I make sure it's nice and straight and go from there.

Another thing to watch out for is the excessive clearances the pool heater will require to walls, pool itself, intake openings, neighboring property, etc...

Offline NoDIY

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Re: Pool heater underground piping
« Reply #6 on: July 03, 2020, 10:58:48 PM »
Techincally 4 elbows is needed for a proper swing,

The current 3 elbows you see on Enbridge riser is on a plastic service... There is a settlement loop below grade... That is why there is not a 4 elbow setup on newer areas..

On steel services you will see a 4 elbow swing used.

Offline walker

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Re: Pool heater underground piping
« Reply #7 on: July 04, 2020, 12:03:42 PM »

I had not considered the swing joint.  Where do you find that requirement?

It's definitely a requirement. Inspectors look for this every time with an underground run.
It's not in our code book (I can't understand why it wouldn't be included). It's either found in the installation instructions for underground piping, pool heater instructions, or enbridge has it in their set of guidelines.
You need to have a minimum 3 elbow swing joint. (Similar to how enbridge has a 3 elbow swing with their meter assembly). In many instances, you can't quite pipe it correctly for a 3 elbow swing, you may need to make it an even uglier 4 elbow swing.
It's all for frost movement. It needs to have these joints for movement of up/down side/side. Without it, a black iron fitting can snap clean off from excessive movement.

...You also need to use their special dielectric unions for the risers. If you really hardly ever do these installs, you don't need to invest in the chamfer tool. The pipe will slide into the risers without it but the tool does make it slip in a little nicer. You need to push the pipe in with all your might to make sure it's seated fully. Usually works a lot better with two guys. I usually secure a valley hanger on the riser to the wall, and then install the union and another piece of black iron with another valley hanger. I make sure it's nice and straight and go from there.

Another thing to watch out for is the excessive clearances the pool heater will require to walls, pool itself, intake openings, neighboring property, etc...

do you have a link to the unions that are required, I've only ever seen the regular ones that are used indoor

Offline walker

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Re: Pool heater underground piping
« Reply #8 on: July 04, 2020, 12:05:03 PM »

Offline walker

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Re: Pool heater underground piping
« Reply #9 on: July 04, 2020, 12:06:38 PM »

Offline Admin

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Re: Pool heater underground piping
« Reply #10 on: July 04, 2020, 12:55:49 PM »
Those links don’t show a product for me.

I think distributors use dielectric unions on the gas supply because of dissimilar metals but I’m not 100%.

You would normally install an outdoor shut off valve on the underground riser than a nipple and union and I don’t know of any Code that says the union must be dielectric. 

For example the Hayward pool heater manual says it’s recommended to use a ground joint union.  I don’t see why you even need a union if you used a gas connector with CSA 6.27 approval.


Offline walker

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Re: Pool heater underground piping
« Reply #11 on: July 04, 2020, 12:58:00 PM »
Those links don’t show a product for me.

I think distributors use dielectric unions on the gas supply because of dissimilar metals but I’m not 100%.

You would normally install an outdoor shut off valve on the underground riser than a nipple and union and I don’t know of any Code that says the union must be dielectric. 

For example the Hayward pool heater manual says it’s recommended to use a ground joint union.  I don’t see why you even need a union if you used a gas connector with CSA 6.27 approval.

Ok I'll just use regular ones.  They wouldn't be able to tell once it's painted anyways I assume.

Offline Porcupinepuffer

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Re: Pool heater underground piping
« Reply #12 on: July 04, 2020, 03:30:05 PM »
The union has one side with a unique look to it that will still show when painted. I believe it's required more for stray current issues than for dissimilar metals.

https://www.boone.ca/en/product-catalog/hvac/gas-piping-fittings/dielectric-unions/