Aqua Hot question

[Keith Moffett]

In the 07 Thunder the AH is just ahead of the rear tires on the passenger side.  Does anyone know why there is a 3 or 4 inch hole through the floor?   This looks like where the relief valve releases when over hot and just hits the ground but the hole is so large it seems there must have been a cover.  The inside of our AH is loaded with road debris and mice would love it in there.
Seems weird to me.

[Jeff Watt]

Keith,

On mine the relief lines are small and back under the side somewhat and go through small holes, certainly not a 3” hole. However my freshwater drain pipe is in the same bay and if it wasn’t there, it would be a 2-3” hole. I assume your freshwater drain is also plumbed out that side.

So, I have no suggestion or idea why or what the hole was for.

Jeff

[Frank Bergamo]

Keith, the hole you are referring to is probably the air intake for the AH burner. It should have a rubber extender coming down off the AH. It may have came off or someone removed it. I have read that they sometimes collapse while drawing in air when burner is on, pinching off air flow to combustion chamber, creating an over rich condition. Hope this helps.

[Keith Moffett]

Keith, the hole you are referring to is probably the air intake for the AH burner. It should have a rubber extender coming down off the AH. It may have came off or someone removed it. I have read that they sometimes collapse while drawing in air when burner is on, pinching off air flow to combustion chamber, creating an over rich condition. Hope this helps.

Frank, that makes sense.  The burner head is right over this hole and so the air intake is too.   Now what to do about it.  lol

[Bryan Schmidt]

Keith

On our smaller Hydro Hot HHE-200-09E, the service manual on pg 30 says: (when servicing the burner)...

“NOTE: If the Diesel Burner Does not align properly, it may be necessary to remove the air intake sleeve and discard. If the air intake sleeve is discarded, it is recommended to install a wire, mesh screen over the air intake hole, underneath the die- sel burner. It is recommended to use a 1/4” hole wire mesh screen.”

[Frank Bergamo]

Keith, if everything lines up properly, you could try to reinstall rubber inlet tube and see how AH works. If not satisfied with results, Bryan's solution to cover hole with wire mesh should do the trick. Keep us posted with results.

[Keith Moffett]

This is the first time I have pulled apart this AH.  I was surprised by the hole through the floor.  I had the AH on all winter to just keep the basement warm.  This hole in the floor seems to be at odds with an insulated basement.  A wire mesh might keep rodents out but not road debris. And certainly not the cold.
Thanks for the feed back and I will update.

[Jim Nichols]

Next time you have it serviced ask any A/H service tech like John Carrillo for the wire mesh. That rubber boot was a air restriction on ours. It was recommended to put the wire for road debris and rodents.  Usually the A/H is not on while moving as the engine keeps the unit hot.