Lennox CR33 condensate causing short cycling

keiths5n10 · Feb 27, 2017

Dealing with Lennox furnace, problem is condensation not draining - trapped & causing it to short cycle. Problem lies inside unit , small elbowed hose, no blockage.. gurgling is heard. Once pulled off drains & runs fine, thinking it needs more of a grade to box?
CR33-3036B
Mod.RP92M34
I feel positive it a design problem

HVAC_Marc · Feb 28, 2017

where does the end of the drain go?

it's not a design problem. it's likely an installation problem

keiths5n10 · Feb 28, 2017

HVAC_Marc said:
where does the end of the drain go?

it's not a design problem. it's likely an installation problem

It's interior, goes into blower? Induction box? Only 5 or 6 inch hose. Will go for a month or so then short cycles. I'll let exterior drain (pull rubber cap) won't cycle, then pull the inside hose off drain water put it back on & she'll take off then , no short cycle . Nothing comes out but water, no crud to block passage. I don't know.. Keith

HVAC_Marc · Feb 28, 2017

A CR33 is an AC coil. Are you taking about a furnace condensate line?

most rubber tube problems ive seen are due to garbage blocking the ports, a few years ago there was a tech bulletin regarding collector boxes on some models of condensing Lennox furnaces.

martyinlincoln · Feb 28, 2017

Double check your numbers. As mark mentioned the CR33 isn't a furnace. The RP number doesn't come up as anything Lennox.

jbhenergy · Feb 28, 2017

Line is double trapped causing an air lock in the condensate line? I had a building that when they replaced all the units, the failed to read the new unit had an internal trap, and installed a trap outside the unit. The double trap creaks a vacuum in the line that will keep the water from draining.

keiths5n10 · Feb 28, 2017

Tag- Mod RP92 M34 , PRODUCT #18455200
Another T11C10331..
M/N ML 193DF070P36B-01
I'm about too shorten tube , connecting upright / exshust
Vent ? So the grade back to the box is for sure draining back into it. Quite a bit of water dumps out when removed to stop short cycling, enough to cover area under burners /ignitor.
It's a lennox, got pics of tags/manufacturer plates from 2 areas.

jbhenergy · Feb 28, 2017

post an overall picture of what is going on so we understand what you are trying to tell us please.

keiths5n10 · Feb 28, 2017

Just read "double trap"
On exterior trap configuration I'll take a clamp / rubber cap & get a little water, kind of like a gas line , leg for debris
So that's the culprit, external trap/drain?

keiths5n10 · Feb 28, 2017

I've got the replacement hose in my truck, first thing I found was installing it they gouged a hole in hose while tightening gas line, a little silicone plugged that. But a month or so starts short cycling again, pull hose - drain & it's good for awhile

HVAC_Marc · Feb 28, 2017

so you have a 93% downflow furnace. The tube needs to be connected to the downflow position. It's in the book.

keiths5n10 · Feb 28, 2017

jbhenergy said:
Line is double trapped causing an air lock in the condensate line? I had a building that when they replaced all the units, the failed to read the new unit had an internal trap, and installed a trap outside the unit. The double trap creaks a vacuum in the line that will keep the water from draining.

I suppose they ship the unneeded trap & installer (very old fellow,1 & only in this small town) just put it together with no regard to newer internal trap.
At first I thought it was a grounding problem causing short cycling.
I know enough to get me in trouble, & this seemed that it had to be something simple, I'll check exterior trap later & post results as I encounter them.?! I'll cross my fingers! Thanks Keith

jbhenergy · Feb 28, 2017

keiths5n10 said:
I suppose they ship the unneeded trap & installer (very old fellow,1 & only in this small town) just put it together with no regard to newer internal trap.
At first I thought it was a grounding problem causing short cycling.
I know enough to get me in trouble, & this seemed that it had to be something simple, I'll check exterior trap later & post results as I encounter them.?! I'll cross my fingers! Thanks Keith

I was not implying that your issue is from a double trap I was just stating that was possible and something to look for.

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keiths5n10 · Feb 28, 2017

Your right, although nothing else is jumping out as the culprit. I haven't come up w anything else & do hope that's the case, just seems really odd what it's doing. K

Lennox CR33 condensate causing short cycling

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HVAC_Marc

keiths5n10

HVAC_Marc

martyinlincoln

jbhenergy

keiths5n10

jbhenergy

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keiths5n10

HVAC_Marc

keiths5n10

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