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Polaris Thumping Noise

Qdog Member Posts: 2
Hi All,

I have a 1 1/2 year old Polaris 50 gallon Natural gas heater (130,000 BTU model). Everything was working perfectly until about a week ago. Now, whenever it ignites, there are a few (ranging from 1 to 5) loud thumping noises before the ignition. There are no error codes, it ignites and heats fine and there are no other noises. There haven't been any changes to the gas, exhaust, etc... It just started happening one day. Our natural gas line is 2# with a reg, if that makes any difference. In that year and 1/2, it has been flushed a couple times and each time, there is no visible sediment coming out.

I've tried everything that I could think of...loose venting, pipes banging, flushing, took off the air intake and fired the tank (in which case the noise was a bit quieter, but still there)...

I'm not opposed to calling someone in to take a look and troubleshoot, but I would prefer to cover off any other simple possibilities myself if I could.

Thanks for your time...Any help is appreciated.




  • Plumdog_2
    Plumdog_2 Member Posts: 873
    try cleaning the condensate trap

    Where the exhaust comes out there is a trap which seals the condensate drain from allowing exhaust gas to escape. Sometimes "stuff" will accumulate and partially block the exhaust; or prevent the unit from firing.
  • AFred
    AFred Member Posts: 81
    polairs 'thumping' on start-up

    I had a similar issue with a new unit.

    After wasting way too much time, I finally put the monometer on it to check incomming pressure. I should have checked that first!

    Did you figure yours out?

  • 4stranger
    4stranger Member Posts: 1
    Polaris Thumping Noise

    I have a Polaris PBG-102 that exhibited the exact symptoms as your unit. First off, I'm no heating guy...but I was forced to learn a lot about American products due to the lack of American Heater techs in my area (Upstate NY). My unit is combined with an air handler component from an earlier American heater, which supply's both heat and hot water for my house. I went thru the same diagnostic checks, drain tank, check for obstructions, etc and spent what seemed like many hours on the phone with the techs at American...nothing seemed to help...sounded like my unit was "out of time" and backfiring upon start up, but not every ignition cycle. No red light diagnostics to indicate the cause of the problem other than the occasional reset after 3rd try at ignition. Finally, out of desperation, I swapped out the electronic control (which luckily was still available from American).....that was two years ago and the unit has run flawlessly since.....hope this helps.... 
  • Qdog
    Qdog Member Posts: 2
    Polaris Thumping Noise

    Thanks for the reponses...I've been out of town for the past couple weeks and I'm back now so I need to figure this out. It's still doing it, but now, not on every cycle now. The condensate is flowing freely but I will give this a check.

    I will also get my hands on a monometer and check the pressure. I know we have 2# with a separate regulator going to the tank, so maybe the regulator is hooped. What should the gas pressure be?

    Replacing the electronics sounds expensive so I guess I'll call somone in first if the gas pressure test doesn't pan out.

    Thanks again and I'll let you know how I fare.


This discussion has been closed.