condensation on my new heater's gas line

[ajw22]

It still seems excessive to me.

It seems that the newer heater designs produce more condensate as engineers try and squeeze more efficiency from them.

Almost all the pool heaters we deal with are 20+ year old designs.

The Avia is a new design that we are slowly learning what its quirks are.

The Pentair UltraTemp ETI hybrid heater is another recent design heater whose gas heater has condensate issues and Pentair talks about installing a condensate trap in the exhaust.

 

[JamesW]

The Avia is a new design that we are slowly learning what its quirks are.

This is why we should ask Raypak if the performance is as expected or if there is an issue.

Since we do not have a lot of examples for comparison, we need to rely on the manufacturer to say "Yes, it's fine" or "No, it is not ok".

 

[ajw22]

This is why we should ask Raypak if the performance is as expected or if there is an issue.

Seems like pool equipment manufacturers prefer treating their users like mushrooms.

Can't hurt to ask. I would not hold my breath on getting a definitive answer.

TFP would welcome manufacturer participation in supporting their products.

 

[1poolman1]

16 years. With the top vent, the heater let a lot of rainwater in and the last rainstorm finally rusted it out too far to repair.

Condensation is very corrosive, even on galvanized pipe.
If you aren't going to re-route the pipe (which really should be done), at least cover it. A piece of 1" PVC can have a slot cut in its length and then fit over that pipe. Use a little silicone sealant to hold it in place.
Had to do that when a plumber installed a new 1.25" gas supply for a customer's heater and routed it above ground, but right under the A/C condensate line. Used galvanized as well. Within 2 weeks a rust spot was forming. Covered it with a piece of PVC about 2' long and there have been no issues for the last 5 years.

 

[bad144]

Will try to find out from raypak what the allowable gas pipe clearances are. They didn't specify them in the install manual. Since the unit is built with the gas inlet 2.5" from the vent cover I'd hope the clearances can be pretty minimal, but it doesn't seem to be the case.

While I initially thought the condensation got better at warmer temps, this was apparently just due to my trying a drip pan under the gas pipes. When I do that, the concrete quickly dries up completely and the pan evaporates the drips pretty fast too. When I take the pan away I have a sizeable puddle on the concrete again in 20 min or less regardless of ambient temp or pool temp.

I would tend to agree that the condensation seems excessive, I don't get such humid air from my tankless water heaters and they produce no drip.

If I watch closely the heater will sometimes make the sidewall of the heater sweat and I even saw a drip at the bottom of the vent cover at one point.

> The exhaust should be mostly going out of the top and not the bottom.

It's blowing both up&down though the down direction is mostly covered. My hand gets wet from condensation whether I put it above or below the vent cover.

> Does the hot exhaust hit the line and cause it to heat up?

Yes in that the line is below ambient temp otherwise, and warmer than that under the exhaust (not actually hot though).

> Remove the door and look for any type of a leak.

Will try but don't think I'll see anything as the base area dries completely with a drip pan under the pipe.

> There are 25 mentions of condensate in the Avia Installation Manual to signal that they realize the heater produces condensate in the exhaust and it needs to be managed.

Most of those mentions don't apply to my case of an outdoor install on a pool equipment slab with no factory vent (no additions). If that scenario requires some special drip management they need to explain what that is. My read of the manual is that this case is "Category III" which is supposed to need no condensation management.

 

[bad144]

Condensation is very corrosive, even on galvanized pipe.
If you aren't going to re-route the pipe (which really should be done), at least cover it. A piece of 1" PVC can have a slot cut in its length and then fit over that pipe. Use a little silicone sealant to hold it in place.
Had to do that when a plumber installed a new 1.25" gas supply for a customer's heater and routed it above ground, but right under the A/C condensate line. Used galvanized as well. Within 2 weeks a rust spot was forming. Covered it with a piece of PVC about 2' long and there have been no issues for the last 5 years.

Agree. Waiting on raypak info before proceeding.

 

[Ahultin]

Easier said than done. The gas line comes out of the concrete in front of the heater, see pics. I'm thinking the most practical would be for the vent to be extended to vent further away from the unit.

Gas line could be easily re-routed up an over the exhaust. Replace the elbow coming off the gas pipe out of the concrete with a coupler, add what looks like ~18" nipple to elevate the run over the exhaust. Run horizontal over the exhaust, 90 down to the union, tee connected to the unit and sediment trap below. If the added nipple is double the current tee to elbow at the unit, it's likely the only component needed is the one riser nipple.

 

[Ahultin]

I would tend to agree that the condensation seems excessive, I don't get such humid air from my tankless water heaters and they produce no drip.

If the tankless is installed correctly, you wouldnt see the condensate (if it's not installed correctly you wont see it till it's too late and will be replacing a tankless due to heat exchanger leak over Christmas break like me )