Starite Heater Noise

I have a Starite Max E Therm 200 k btu natural gas heater that makes a really annoying resonating whining sound. I've been working on diagnosing it and have narrowed it down to the airflow through the suction side of the heating blower. When the cover is on the heater it makes the noise, as soon as I remove the cover the noise goes away. I can replicate it by partially obstructing the suction side of the blower with my hand and the sound comes back, as soon as I move my hand away the sound goes away.

Any suggestions on what to do, or has someone experienced this before?

Thanks in advance.

Hi, welcome here!!:)

The noise is usually because the gas/ air mixture is either too much or too little, which makes sense with what you describe. I would strongly suggest that you get your gas company out there to adjust it! If you want to do it yourself, I can tell you how to make the adjustment, but it wouldn't be the optimal/ safe way to do it:(

Waste,
Thanks for the reply. If you don't mind explaining it, I'll take you up on your offer. Not that I'll necessarily do it myself, but I'm curious and an engineer and wouldn't mind knowing for future reference.

I did call my pool builder a few weeks ago about this (because my pool still under warranty). They came promptly, made an adjustment and said it might take a couple trips to get it right. That didn't seem right that it might take a few trys, but what do I know? I will call them again next week to get them back out. Or do you really recommend that this is a job for the gas company and not PB?

The community on this website is an amazing group of people and I've learned a ton about pool care. I've also read many of your posts and have learned a great deal from you.

Thanks again!
Andy

24K gal vinyl IG
200 LB Starite sand (with a little DE added :D ), 1hp Starite pump
200k btu Starite

Andy, no problem. All to need for this is a screwdriver:) , though a 5/16" nutdriver makes it easier to remove the screws that hold the cover together. I remove the bottom 2 first then the top 2 - when you take out the last screw use your knee to hold the front 1/2 and your free hand to catch the back side (keep track of the screws! - they have a tendency to wander off). Turn on the unit and adjust the desired temp so that the unit will continue to heat and make the noise.

OK, now that the cover is off, step around to the backside of the unit and locate the "combination gas control valve", which is very easy as it's the box on the gas line with the on/off switch or knob. On the left side you'll see a ~ 1/2 " screw - unscrew it to reveal another screwhead. The revealed screw adjusts the flow of gas to the heater, this is what you'll use to fix the problem. TURN THE SCREW SLOWLY AND NO MORE THAN 1/8 OF A TURN AT A TIME!!!!! - this is a very sensitive adjustment. Always give it a few seconds between turns. If you turn it clockwise and the noise gets louder or worse, wait a few seconds and turn it counter clockwise. Make any adjustments using small turns (I can't stress this enough!), this is why the pool guy said it may take a few visits to nail it down - the 'sweet spot' is usually very small. You may have to adjust it a few times to get it to stay quiet - if it goes from 'whining' to 'fluttering' you've gone too far.

If anything unusual happens while you're doing this, shut off the unit and kill the gas to it and call the gas company!!!!!

I hope that I've empowered you to be able to take care of it yourself, be safe! while playing with it. - Ted

Ted,
Thanks for the detailed instructions. I can definitely follow those if I need to at a later date. For now I'll leave the adjustment to the PB, but at least I'm empowered if it starts again.

My problem is so intermittent, I share this in case it generates any other thoughts. The noise only starts after the heater has been running for a while (30 mins plus) and seems to occur some days and not others. I'm guessing the intermittent sound could be because of atmospheric conditions, temp, pressure and RH. For example on Saturday it was howling after 1/2 hour of running and it would fade in and out, but Saturday it was mostly noisy. It's a shrill almost painful harmonic. As I removed the cowling on the side of the blower inlet the noise stopped and as soon as I'd put the cowling back on the noise would come back. It's hard to believe that the cover could change the airflow by that much? However from what you've told me about how sensitive the adjustment is, it would seem to me that I must be very close to the ideal setting.

It's a beautiful fact that I'm worried about my heater here in Rochester NY on October 1st and we're still swimming outside. It's been 75-80 almost every day and expected to be so for the next 7 days. It's been a great first year for our pool, swimming since May 9th and counting.:D

Thanks again.
Andy