My heater is whistling 😙

[BodeFamily]

I have an old Hayward FSN250 heater. We just had to have the valve inside replaced, because it wasn’t letting any gas through (the switches were frozen in the off position). Our HVAC guy did that work.

I just fired up the heater because it’s finally going to be warm enough to swim this week. But as soon as the ignition kicks on, the heater makes a really high-pitched whistling noise that you can hear clear across the yard and house: pretty sure the neighbors can hear it. I checked to make sure the valve was all the way open, and when I was moving it around the pitch changed.

I’m guessing a problem with gas flow/pressure? Any ideas or troubleshooting? I might send the whole neighborhood to the loony bin if this keeps up all summer!

 

[Poolbreh]

Was the gas valve the only thing replaced?
Is there a part number on gas the valve?

 

[1poolman1]

I have an old Hayward FSN250 heater. We just had to have the valve inside replaced, because it wasn’t letting any gas through (the switches were frozen in the off position). Our HVAC guy did that work.

I just fired up the heater because it’s finally going to be warm enough to swim this week. But as soon as the ignition kicks on, the heater makes a really high-pitched whistling noise that you can hear clear across the yard and house: pretty sure the neighbors can hear it. I checked to make sure the valve was all the way open, and when I was moving it around the pitch changed.

I’m guessing a problem with gas flow/pressure? Any ideas or troubleshooting? I might send the whole neighborhood to the loony bin if this keeps up all summer!

Is the sound coming from the blower? It is the first thing that starts as the ignition cycle begins.

 

[BodeFamily]

Was the gas valve the only thing replaced?
Is there a part number on gas the valve?

Not sure if this is the part number, but this is what was replaced. The control board was also replaced because the buttons weren’t working. But none of the gas lines or fixtures were changed.

 

[BodeFamily]

Is the sound coming from the blower? It is the first thing that starts as the ignition cycle begins.

So I hear the clicks before the ignition, the. I hear air start to move, then the whistling starts. Does that make sense?

 

[1poolman1]

So I hear the clicks before the ignition, the. I hear air start to move, then the whistling starts. Does that make sense?

Turn the external gas valve "off" and try the ignition cycle. If the whistle continues it is not in the gas section but may be the bearings in the blower motor. You will get an "IF" error.

 

[BodeFamily]

Turn the external gas valve "off" and try the ignition cycle. If the whistle continues it is not in the gas section but may be the bearings in the blower motor. You will get an "IF" error.

Ok, with the gas off I hear the ignition clicking, and it sounds like it wants to start but doesn’t. It did that a few times, and then I got the IF error displayed on the screen. No whistling sound.

 

[1poolman1]

Ok, with the gas off I hear the ignition clicking, and it sounds like it wants to start but doesn’t. It did that a few times, and then I got the IF error displayed on the screen. No whistling sound.

You've isolated the problem to the gas supply. Is this propane? If so is the valve at the tank completely open? A whistle in the gas system is usually an indication of low gas pressure. If there is a separate gas cock at the natural gas meter for the heater only (sometime these are installed) is it completely open? A new main gas valve should not be the issue, but I've seen stranger things with a pool.

 

[BodeFamily]

You've isolated the problem to the gas supply. Is this propane? If so is the valve at the tank completely open? A whistle in the gas system is usually an indication of low gas pressure. If there is a separate gas cock at the natural gas meter for the heater only (sometime these are installed) is it completely open? A new main gas valve should not be the issue, but I've seen stranger things with a pool.

It’s natural gas, and plumbed into the lines in the house. I followed all the lines and don’t see anything that isn’t open. I may just give out HVAC guy a call in the morning and have him come check the pressure coming through the line . Could be a valve somewhere else gone bad, or maybe a small leak? Either of those are well outside my capabilities to fix!

 

[Poolbreh]

Improper air/gas ratios can cause a whistling noise. Since the valve is the only thing replaced. My guess is the valves regulator is outside the requirements.

 

[BodeFamily]

Ok, update on my whistling heater and a new question!! Had the HVAC company come out and check for leaks in the supply lines. Everything is good there. They also cleaned some soot out of the heater where it wasn’t burning right.

Got a hold of a manometer and checked the gas pressure on the new valve. At the manifold it was up over 4, so adjusted that down to the proper range and the whistling went away. Whew!

Then started getting an IF error. Replaced the igniter, and everything now fires up correctly. However every few seconds there is this knocking sound, kind of like you hear when it first ignited and the blower kicks on.

I’m wondering if this is something to worry about or not. Like is this normal with a new igniter or once the pressure has been adjusted. I tried to attach a video, but it wouldn’t upload. So I threw it on You Tube if you’re interesting I’m taking a listen to see if you have any insight.

Thanks as always for your help!

 

[Poolbreh]

Make sure flow is adequate(30gpm). Clean filter if necessary, close any external bypass if open. If it continues check internal bypass and the inside of the exchanger for build up.

 

[BodeFamily]

Make sure flow is adequate(30gpm). Clean filter if necessary, close any external bypass if open. If it continues check internal bypass and the inside of the exchanger for build up.

If the heat exchanger had buildup, is that best cleaned off with a shop vac? Some water? A particular chemical? Just want to be prepared if I’m opening up the beast, lol.