No rear target wall on Peerless Pro

Dave M

I maintain 5 boilers in rentals. One of them is a Peerless Pro3 water boiler and I'm wondering why it does not have a refractory ceramic target wall at the rear of the combustion chamber. It has refreactory insulation on the inside of the front swinging door and a blanket on the bottom of the chamber but nothing on the back. The flame fires right against the cast iron. The other boilers , some of them Peerless, all have a rear target wall. Is this common and OK? I don't see the rear insulation in the parts diagram. I just don't want to ignore this if it's going to cook the rear cast and shorten the life of the boiler. I would think that exposed iron would be more susceptible to flue gas condension too. This boiler is 3 years old. Thoughts?

Robert O'Brien

Triple pass

 it doesn't have any target wall

STEVEusaPA

true it doesnt need a target wall

But, is the flame impinging on the back wall? That's definately no good.  The likely culprit is the wrong nozzle.  Hopefully you have the original installation instructions (or you could download them) to find the OEM installed nozzle type, size & brand, and at what pump pressure.  Make sure you check the pump pressure to match the original.  If  the pump pressure was changed (pump change) from 100 psi to 140 or 150, you'll have to compensate with a change in the nozzle.

Dave M

Rear target wall

The actual flame doesn't reach the rear wall but the radiation sure does. It's my understanding the ceramic insulation protects the cast from the radiation. The back of the front wall has insulation as does the floor of the chamber and those never get flame, just intense radiation. It makes sense if they protect the front and bottom that they'd protect the back. I would think that would recieve the most radiation and I'm surprised it isn't protected.

The nozzle used is the correct one (.5 gallon - 60 degree Danfoss AS) and the pump pressure remains at 140. No changes have been made, it's only 3 years old.

I don't see why it would matter if it's a pin style or a triple pass, it's still a combustion chamber.

kcopp

The type of.....

cast iron is different. Whether they call it GG20 , GL-180 it is "flexable."  As are most of the 3 pass boilers....  Biasi, Buderus, Pensotti, Viessman...etc. None of them have a rear refractory. The blanket they have you put on the bottom is more for noise than anything else. Lots of installs never an issue...

R Mannino

No Refractory

at all in the Buderus, but it is quietest of all with the Beckett NX