# Thread: Pool Heater and Gas Line

1. ## Pool Heater and Gas Line

Is it possible the installation of a 250 000BTU gas heater could affect the other appliances in my home? Is it a situation where if I am using my pool heater, I can't use my furnace or fireplace? Or would I have to increase the size of the meter?

2. ## Re: Pool Heater and Gas Line

If you don't already have a meter with enough capacity, you will need to get a new one that does. If you add 250,000 BTUs to a meter that is already near capacity it will cause problems for anything turned on at the same time as the pool heater. This is usually only a problem for older homes, but it is always worth double checking.

3. ## Re: Pool Heater and Gas Line

Our house is about 10 years old and we have a gas hot water tank, furnace and fireplace. Any way to check the capacity and usage level?

4. ## Re: Pool Heater and Gas Line

The gas meter should be labeled. Your current equipment should total less than 200,000 (rough guess). Each individual piece of equipment will be labeled in BTU somewhere, if you want to add them up exactly.

5. ## Re: Pool Heater and Gas Line

You'll probably need to get a plumber that is familiar with gas requirement calculations to look at your current setup. Similar to pool pump installations, there are many things to consider. The diameter of the gas pipes and their length has an effect on the volume of gas that can actually be delivered to the end of each individual gas pipe within a certain time frame. The calculations need to be performed using the worst case scenario (ie, how much gas can flow if ALL gas appliances happen to be on at the same time).

It takes a LOT of gas just to provide that 250K BTU's of heat to your pool. You also need to look at the INPUT requirement on the heater. An 80% efficient heater that has a 250K BTU output requires about 313K BTU's of gas input. The other 20% of the BTU's goes right up the flue.

The solution could be that you just need a meter that is capable of higher flow. But it could also require a larger feed (pipe) from the street, and/or that the pipes within the house need to be bigger. A plumber with the right knowledge can do the calculations and determine what you need to do to be able to provide enough flow to run everything at once. It might be worth a shot to ask your gas provider first, as they may send someone out to check things over for free.

6. ## Re: Pool Heater and Gas Line

Sure, it will require a professional at some point. But you can get a good approximation of what will be required just by reading the label on the meter and making a few guesses about how things are setup.

7. ## Re: Pool Heater and Gas Line

So I read the meter and it says it is a Metris M250. 250 CFH at 0.5 inch and 400 CFH at 1 inch, H2O differential. It also said 7.1/5.5 gas/air, cubic meter. Assuming I have half inch piping, can it be changed to one inch? I called the local gas company and they were useless.

8. ## Re: Pool Heater and Gas Line

Most residential applications use 0.5" of pressure (not diameter), so you are almost certainly going to need to upgrade the meter/gas service. The exact way this happens varies a bit from place to place. Here, I needed to have a licensed master plumber install the new piping and get that approved. The the plumber helped me write up the application for upgraded service, which I had to submit to the gas company. Then the gas company sent someone of their own out who upgraded the meter, then my plumber came back and made the final connections. In some areas you have to use a plumber that is approved by the gas company and they do everything. Sometimes the property owner has to request the service upgrade, sometimes the plumber has to make the request.

The next step is to find a licensed plumber to do the work, and get a bid from them. As part of the process of getting a bid, you can talk to them and find out if they deal with the gas company or you do. They can probably also give you an idea of how long it takes your local gas company to do the upgrade.

9. ## Re: Pool Heater and Gas Line

Does anyone know how I can tell if my meter is set up for 400 CFH or 250? My calculations are that a 250 000 BTU heater requires 227 CFH of gas. My totalling of my other household items that use gas comes to 173 CFH.

10. ## Re: Pool Heater and Gas Line

Call your gas company... when my pool was built, the gas company happily came out and installed a larger high flowing meter for free. They're eager to be selling you more natural gas so they are happy to give you the new meter.

11. ## Re: Pool Heater and Gas Line

It is very very likely that it is setup for 250 CFH. The only way to tell for sure without asking the gas company would be if the pressure regulator (a device before the meter, usually with an extra vent pipe coming out of it) is labeled, but they often are not labeled in any obvious way.

12. ## Re: Pool Heater and Gas Line

I agree with Jason -- often (and in this area) they will come out and install a bigger one for free. I understand there may be warranty issues with the heater (don't know why) if you don't have a big enough meter.

I guess I should get that done....

13. ## Re: Pool Heater and Gas Line

Called the gas company, they faxed me a form and wanted to know how much gas I used currently and how much I would need in addition to my current usage. They said they will send someone out to check the meter and the line to see if it is already sufficient.

14. ## Re: Pool Heater and Gas Line

Starving a gas heater with insufficient gas pressure will usually cause a "bad flame" which creates sooting, and that interferes with the excange of heat in the coils (the heat exchanger). It also can damage the exchanger.

The specs for the proper gas pressure are in the Owner's/Installation manual of the heater you own. If you can't find it, it's available online. I have seen numerous installations where the gas line is "shared" with the household appliances, to the demise of the heater and it's operation.

Also, please quit trying to engineer your gas pressure, line size, etc., unless you have a manometer to determine your actual pre- and post-gas valve pressure. That's what the gas company gets paid to do, and you want to have them on the hook for performance. If you "advise them", other than showing them the requirements of the manufacturer, you risk being the one at fault for it not working.

I'm sure you will get it done right! Good luck.

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