Pentair Mastertemp 400 ng combustion chamber cover bolts

loweran · Oct 31, 2015

I have been working on replacing my blower that went out. The combustion chamber cover and bolts are rusty since I had to put some bleach and water on it due to a nasty rat nest and droppings.

When I was replacing the blower plate on top of the chamber, I snapped off a bolt that secures it to the cover.

Does anyone know if those are replaceable? I have not taken the cover off yet, but will need to do so to get to the bolt. I am considering replacing the cover, but I think it is still serviceable.

Thanks!

ps0303 · Oct 31, 2015

I've never looked to see how the come thru the other side but I would have to guess they are some how welded into place. Lots of work to replace one of those bolts if possible.

loweran · Nov 1, 2015

ps0303 said:
I've never looked to see how the come thru the other side but I would have to guess they are some how welded into place. Lots of work to replace one of those bolts if possible.

Well the cover has to come off either way. If they are truly welded, I may consider replacing the cover. I would like to replace all the bolts while I have it off. The instructions said to torque to 80 lbs but that seems to be too much for the hardware on the cover.

ps0303 · Nov 1, 2015

You'll be better off replacing the cover but it's going to be over $300 probably. I don't use a torque wrench I tighten them with a ratchet.

I wouldn't personally spend all that time and money on the unit but that's just me. You're half way into a new heater when you add up all the costs. How old is this unit?

loweran · Nov 2, 2015

ps0303 said:
You'll be better off replacing the cover but it's going to be over $300 probably. I don't use a torque wrench I tighten them with a ratchet.

I wouldn't personally spend all that time and money on the unit but that's just me. You're half way into a new heater when you add up all the costs. How old is this unit?

The heater is just 4 years old. I would hope to get more service out of it than that.

ps0303 · Nov 2, 2015

Well then being that new I'm surprised the blower went. That doesn't speak very well of their product life. That blower should have lasted many more years than that.

When you replace the cover, you don't need to crank down very hard on the nuts. Like I said, I do not use a torque wrench just a ratchet and tighten them down.

loweran · Nov 9, 2015

I have two choice words for this heater. I will let you guess the words.

I removed the combustion cover. In the process, I broke the igniter, and when I pulled the cover. I pulled the insulation apart. I assume I could reuse the insulation, but might look at replacing it since I have it apart. The bolts are permanently fastened to the cover. I would replace them with a lot of work and a torch, but since the cover is sort of rusted, I guess I will replace it.

ps0303 · Nov 9, 2015

Now you see why I replace these units when this happens. It seems like easy work but it's not. Not even for someone like me that has been doing gas pool heaters for a long time. It's a live and learn type of thing.

loweran · Nov 9, 2015

Yeah. It's just frustrating how fragile they are. I get the igniter disintegrating, but the bolts snapping and the fact that they are part of the unit. It should not have been that big of deal to replace the blower. For that matter, it should be designed to replace the blower motor and not the whole dang thing. Poor design in my opinion.