atwood water heater issue
What you describe is a blockage somewhere between the air shutter (slotted thingie) and the exhaust. It’s basically backfiring because the flame is blocked.
First make absolutely sure the entire flame path from the slotted area out the exhaust is free of wasp and mud dauber nest material. Run a bottle brush through the entire flue, then use compressed air to blow out the junk blowing at the air shutter end only. Wear eye and face protection. There may be flying bits of stuff, dead bugs, etc. Coming your way at high velocity.
If you have to disassemble parts to clean fully, take pictures first. Don’t ask how I know this...
Clean and reassemble. Then the ‘shutter’ gets adjusted, with the flame on, until it is a steady, relatively quiet blue flame. Yellow indicates too much gas, not enough air. Make sure the water heater has water in it for this step!!!!
A tiny adjustment to the shutter makes a big difference. Be gentle and gradual. Tighten the screw gently. It can easily strip out and screw up everything....and make keeping the adjustment set very difficult.
Rich, KE4GNK/AE, Overkill Engineering Dept.
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