URGENT: gas pipe diameter for Hayward H250FDN!!!

[Corsara]

Hello everyone, I am in need of urgent opinions!

Tomorrow morning a contractor will be installing a gas line for my new Hayward H250FDN heater. This is a new heater, my pool never had heating before.

The problem: the distance for the new gas line will be about 70-75 feet, and the gas supply is what is "natural gas low pressure". According to the heater manual, a pipe with diameter 1 1/4 should be used for 50-100 feet. However, my installer insists that the 1 inch pipe is fine.

Please, tell me what you think about that, because I'm about to freak out

 

[JasonLion]

Unless the pressure is higher in the pipe and then brought down right before the heater, you should use the larger pipe. Many of the heaters are picky about being sure they are getting enough gas flow and refusing to work if they don't.

 

[jblizzle]

I am certainly no expert, but according to the sizing calculators and tables I have seen, with that run for a 250,000 BTU heater the requirement is between a 1" and 1 1/4" pipe and typically you size up.

If it were me, depending on the price difference (should be minimal compared to the rest of the work), I would go with the 1 1/4".

I think I have read on here that it can be bad to not have full flow to the pool heater resulting in soot buildup ... another reason to opt for the 1 1/4". This could give you additional capacity to maybe hook up a grill or fire pit (although you probably would have to go even bigger for those big loads)

FYI, when we bought our current house I found that we had a gas furnace, gas water heater, gas dryer, gas fireplace, and gas cooktop that appear to be fed by a 1" line from 100' away. According to the tables, this is WAY undersized. That said ... we do not have problems cooking in the winter when the furnace is on with clothes in the dryer ... they may not be at peak efficiency, but they work without issue. We have a pool heat (400k BTU I think) that has its own line and I think it may be 1 1/2", which is bigger than the house gets for a smaller potential total load.

Edit to add: with the 1 1/4" you would have the capacity for about 400k BTU (maybe a future larger heater?)

 

[Corsara]

Oh well, I just called the contractor and insisted on the bigger pipe. That added $150 to the cost. What started as a $800 installation cost, it's now up to $1,550

 

[jblizzle]

At least you will KNOW that the pipe is adequate ... and will have the possibility of future upgrade/expansion.

Out of curiosity, what ballooned it from 800 to 1400? Excavation more difficult?

 

[Corsara]

Out of curiosity, what ballooned it from 800 to 1400? Excavation more difficult?

Well, due to water pipes, gas line has to go a longer way around the shed, which added about 25-30 feet. Then, I cancelled the order on the millivolt heater and bought the electronic ignition one instead, which resulted in need for electrical wiring. Also, I decided I don't have the proper tools to connect the water to the heater (tools for cutting the shed walls), so the guy will do that too.. all of that increased the price, hope we enjoy the heater though! Up here in Canada it's just June to August without a heater, so I'm hoping to extend the season a bit..

By the way, there's another potential problem: the heater will be connected in series with the pump on the same power line. Pump draws 11 amps, the circuit is rated up to 20 amps, do you think that would cause problems for the heater?

 

[jblizzle]

I don't think that is really in "series" per se ...
I also do not think that the power draw is very much for the heater, so the 20 amp circuit should be fine, although, I am not sure the best way to have it wired in. I thought motors generally liked to be on their own circuit.

Currently, I have a 20 amp 230V line from the house panel to a small subpanel by the pool equipment (old school round fuses!!! to be changed). My pump is then fed from a 230v 15A circuit and then a 120v 15A circuit feeds a GFCI outlet right off the panel. My heater has a standard plug that is attached to the outlet. My pool light is also fed off that GFCI outlet. Scarily ... when we moved in, that outlet was NOT a GFCI and I do not think the pool light had any protection (It think it was just on its own circuit). This was something I changed during our remodel.

May be possible for you to do the same by adding a small subpanel, although it may not be necessary.

 

[threewide]

According to CSA and TSSA code, a run of 80 feet on 1 inch black pipe can handle 290,000btu, however, with elbows and other factors, I would recommend as You did with the 11/4 pipe. Your installer is correct though-sort of. If Your manual calls for bigger pipe, it is best to go with it for warranty reasons. Ahh, warm pool and cold beer...good times

 

[bk406]

By the way, there's another potential problem: the heater will be connected in series with the pump on the same power line. Pump draws 11 amps, the circuit is rated up to 20 amps, do you think that would cause problems for the heater?

The heater only draws 1 amp at 220VAC or 2 amps at 120VAC. It'll be fine. I have mine on the same circuit as the pump. No issue.

 

[jamesmillhouse]

You should be more concerned about the size of your meter being able to handle the additional BTU's required to run the pool heater.

That is the first thing you should have verify. The gas company will know what size gas pipe to install. The Gas Company needs to know what other gas appliances you have.

James Millhouse

 

[rcy]

You should be more concerned about the size of your meter being able to handle the additional BTU's required to run the pool heater.

That is the first thing you should have verify. The gas company will know what size gas pipe to install. The Gas Company needs to know what other gas appliances you have.

James Millhouse

This is true. When I had a tankless hot water heater installed, it was the proverbial straw that broke the camel's back. This one additional gas appliance (in addition to gas fireplace, gas dryer, gas furnace and 250000BTU pool heater) caused the total BTUs of all the appliances together to exceed the capacity of the meter on the house - it didn't matter that I would not be using the house furnace at the same time as the pool heater etc. It was only the total BTU that mattered. The only good news - the gas company installed a bigger meter free of charge.