Heater stopped igniting after whole home generator installation

[dailygenesis]

Hello everyone,

We had a Generac whole-home generator installed today, at least the first phase of it. And, as it seems is always the case, the installation of one thing broke something else. Our Hayward H500FDN pool heater has stopped igniting.

The generator plumbers reconfigured the gas meter a bit to make a new run for the generator. Part of this reconfiguration was installing regulators on the gas lines running to the house and to the pool heater. My understanding is that this is because they will be asking the gas company to increase the overall pressure or flow of the gas meter to accommodate the generator, and they don't want to overdo it on the gas running into the house and to the pool heater.

In theory, it seems this should be fine, even now before the gas company has made this change. The regulators should allow the right amount of gas through now and also if the pressure increases keep the gas pressure at the right level.

But I can't help but think the installation of that regulator on the line to the Hayward has to be causing this issue. The generator company says nothing has changed as far as gas delivery and that it probably just the heater went bad. I find it hard to believe the heater went bad at exactly the same time they made this change.

Anyway, they are sending their plumber back out tomorrow afternoon. I am wondering if anyone has any advice on how I could guide this process. What should they be doing to make sure the gas delivery is right for the heater now and once the gas company increases flow? I would think they should know this but I don't think they are specialists in the pool heaters.

Any help is appreciated.

 

[HermanTX]

Anyway, they are sending their plumber back out tomorrow afternoon. I am wondering if anyone has any advice on how I could guide this process. What should they be doing to make sure the gas delivery is right for the heater now and once the gas company increases flow? I would think they should know this but I don't think they are specialists in the pool heaters.

You have a 500k BTU heater. Tell that to the plumber. 100k BTUs = 100 cubic feet of gas - So you need 500 cubic feet of gas to be delivered to the heater. My hunch is that they set the regulator incorrectly or somehow starving the heater.

@JamesW may have more info to share.

 

[dailygenesis]

You have a 500k BTU heater. Tell that to the plumber. 100k BTUs = 100 cubic feet of gas - So you need 500 cubic feet of gas to be delivered to the heater. My hunch is that they set the regulator incorrectly or somehow starving the heater.

So I just took note that my gas meter says AC-250. Does this mean it’s not even capable of delivering more than 250k BTUs? Because I’ve been using the heater with that gas meter for a year without issue. Wondering what will happen with the generator added?

And thank you for the helpful reply!

 

[ajw22]

So I just took note that my gas meter says AC-250. Does this mean it’s not even capable of delivering more than 250k BTUs?

Cirrect.

Because I’ve been using the heater with that gas meter for a year without issue. Wondering what will happen with the generator added?

Your 500K BTU heater has been running lean putting out about 250K BTU of heat. Someone adjusted the air/fuel mixture in your heater to make it work with 250K BTU of gas.

When your heater gets 500K BTU of gas you will be surprised at how much faster your pool heats.

What model heater are we discussing? Hayward H-Series 500K?

 

[ajw22]

Have the gas pressures checked with a manometer.

 

[ajw22]

 

[dailygenesis]

Your 500K BTU heater has been running lean putting out about 250K BTU of heat. Someone adjusted the air/fuel mixture in your heater to make it work with 250K BTU of gas.

When your heater gets 500K BTU of gas you will be surprised at how much faster your pool heats.

What model heater are we discussing? Hayward H-Series 500K?

Bruh. Yes, that's the correct model.

I guess there's a silver lining in this happening in that I discovered I need to get a bigger gas meter.

Thanks for all the info.

 

[dailygenesis]

Have the gas pressures checked with a manometer.

Yeah, I actually went out tonight to try and get what I needed to test the pressure myself but couldn't find a suitable manometer. Will ask the plumber about testing this tomorrow.

I'm thinking my best course of action might be to ask him to remove the regulator on that side entirely so we can see if the heater works. If it does, that would prove its a gas flow issue and not an unrelated heater issue. From there, we can make a plan on how to get everything sized correctly, which might delay that finalization of the generator install, so we shall see.

 

[HermanTX]

I guess there's a silver lining in this happening in that I discovered I need to get a bigger gas meter.

Also, a gas company will "usually" change out the meter to a larger one free of charge (not sure about the labor) because they know they will get money back on increased gas usage - so you hopefully will not need to pay for a new gas meter.

 

[ajw22]

There is low pressure gas service from the gas company and high pressure gas service.

A 250CFM gas meter would run on low pressure gas service and does not need regulators.

When your gas service is changed to high pressure service for greater gas capacity the meter is changed and regulators are used to lower the gas pressure at appliances to the low pressure it expects.

It sounds to me like your Generac plumber setup regulators expecting the gas company will change your gas service to high pressure. But your existing low pressure gas service will not work through those regulators. I think they left your pool heater inoperative in the transition of your gas system upgrade. You need to talk with the plumber to fully understand what they are doing to your gas service and appliances.

 

[proavia]

Once your gas meter and regulators are set up correctly, a pool heater service should be scheduled to be sure the pool heater is receiving the correct amount of gas and is functioning correctly.

 

[dailygenesis]

It sounds to me like your Generac plumber setup regulators expecting the gas company will change your gas service to high pressure. But your existing low pressure gas service will not work through those regulators. I think they left your pool heater inoperative in the transition of your gas system upgrade. You need to talk with the plumber to fully understand what they are doing to your gas service and appliances.

Yes, this is what I think too. But two things:

1) They also added a separate regulator on the pipe going into the house and everything in the house works as expected. It is only the pool heater that seems affected by the addition of the regulator while on low pressure service. Why would everything in the house work in this kind of set up (still low pressure service but with regulators added) but not the pool heater?

2) In theory, wouldn't the regulator still work on a low-pressure line. I mean, it's job is to just keep the outlet pressure in a certain range. It seems it should still do this regardless of the inlet pressure, right?

 

[BMerrill]

Wrong capacity meter, move regulator within 6' of heater, use correct size pipe using the chart in the heater manual, verify gas pressure at heater.

As for the generator, consider having a soft starter added to the HVAC units.

 

[ajw22]

What color is the flame on your cooktop and othe gas appliances?

The Importance of Understanding Your Gas Stove Flame Color General Parts

Learn why understanding the color of your gas flame is important with General Parts Group. Discover what a normal gas stove flame color should look like

generalparts.com

 

[dailygenesis]

Update: the generator plumber has said that he didn't realize the pool heater was 500k BTU and that the regulator he used is undersized for that. He is coming back today to replace with a new regulator that can handle up to 700k BTU. I am skeptical on whether this will solve the issue, but we shall see.

 

[dailygenesis]

Also, a gas company will "usually" change out the meter to a larger one free of charge (not sure about the labor) because they know they will get money back on increased gas usage - so you hopefully will not need to pay for a new gas meter.

The generator company has put in the request for the pressure elevate. The gas company will contact me directly to coordinate this. At that time, I will talk to them about ensuring the meter and pressure is sized correctly for everything we have going on. Hopefully, we can correct what seems to be something that should have been handled by my pool builder last year.

 

[dailygenesis]

What color is the flame on your cooktop and othe gas appliances?

The Importance of Understanding Your Gas Stove Flame Color General Parts

Learn why understanding the color of your gas flame is important with General Parts Group. Discover what a normal gas stove flame color should look like

generalparts.com

Just ran all four gas burners on high and they all have solid blue flames so I think we're good there. I also ran the heater furnace yesterday after the change and everything worked correctly (I didn't actually look at the flame in the furnace but the heater was running as expected). So, perhaps the regulator is doing what it's supposed to for the house side and it is just a matter of having a higher-capacity regulator on the pool heater side. We shall see.

 

[JamesW]

Can you show pictures of everything?

Maybe the plumber shut off the valves at the heater?

Check the external valve and the internal valve.

Maybe the line got air in the line.

The meter is undersized for the heater, so the heater should be left off until the meter can be replaced.

What's are the gas line size and length?

 

[dailygenesis]

Maybe the plumber shut off the valves at the heater?

Check the external valve and the internal valve.

Maybe the line got air in the line.

I have checked all of the shut offs (internal and external) and am sure they are open. When the heater runs its ignition cycle, I can see it is pulling gas by watching the meter and I can also smell the bit of gas that escapes when it fails to light. So, I am pretty sure gas is getting to the heater. Its possible there is still air in the lines but I have run this quite a few times so it should have been flushed out by now.

The meter is undersized for the heater, so the heater should be left off until the meter can be replaced.

What's are the gas line size and length?

Understood, but the heater has been operating on the current meter and with current configuration for over a year without issue. Gas line from the meter to the heater is about 12 feet and is 1" pipe. Based on what I see in the specs, this pipe seems undersized too (should be 1.25"). This is all stuff I might have to go back to my pool builder to talk about if they installed it with an undersized meter and undersized pipe. But my main concern at this point is just to get it back to operational as it was for a year up to the point of this generator install.

I will work on getting some pics uploaded.

 

[JamesW]

Gas line from the meter to the heater is about 12 feet and is 1" pipe. Based on what I see in the specs, this pipe seems undersized too (should be 1.25").

They can put the regulator near the heater so that you have 2 psi from the meter to directly next to the heater and then the line will be ok.