4 new evap coils in less than 5 years, mold

[dabolts]

I had a Trane XL16i, variable speed air handler and Perfect Fit EAC installed late Nov. 2004. Since then the evap coil has had to be replaced every year since 2006 - a total of 4 times. The last time it was replaced a few months ago the tech said the evap coil was not level and condensation was dripping on the EAC causing an arcing leading to a small leak in the evap coil. Well it has been 2 months and we are now hearing the arcing noise again. Sometimes it sounds like a machine gun! Has anyone experienced this issue or have any ideas on why this is happening? I am concerned this arcing is damaging our EAC as well. Fortunately we have a 10 yr P&L contract.

Also, I recently had a PM and the tech showed me some (small amount) of mold/mildew around the wiring in the top section of the air handler. He tried to sell me a UV light but I am holding off on this. I think the mold/mildew is attributed to the coil going bad so often and not removing moisture from the air system properly. Again any thoughts/ideas would be appreciated.

[dash]

One or more of the coils could have been misdiagnoced,not knocking your servicer,most brands says a significant number of coils returned test fine.Have they checked the refrigerant lines ,between the indoor and outdoor unit,for leaks?

I've heard there was an issue with the new all aluminum coils,do you know if yours is aluminum tubing?This was a mfg. issue and solved now,but some coils are still out there.

Mold/mildew in that area could be from a restrictive return duct system,causing condesate water to blow off the coil.Shouldn't be coming from the return air with your filter,if it's working and cleaned often.

Just some ideas,no conclusions.

[ball a/c]

Tell them you want a coated coil as a replacement this time. That is what give you the best shot at not having a leak. Trane will know exactly what you are talking about. You are blessed that you have a 10 year warranty, but you are paying for the electrical usage when has leaked down.

[BaldLoonie]

Mold in the blower compartment of an air handler isn't unsual. It's in the cold air supply. Usually able to just wipe it off unless it builds up over the years and turns nasty.

As for water leak, could be issues with the coil "raining" and needs to be washed. Could be they are not putting a large enough trap in the drain line.

[jbarron4]

It is very possible that you have a small leak elsewhere and you are receiving a BS diagnosis. I have seen this a number of times.
The last time the tech said that the coil was leaking and needed to be replaced and I asked him to show me the spot with his leak tester. He himmed and hawed and said is was spread out all ovet the coil.
At that I told hin that I would approve the replacement, but if it still leaked he would refund the cost and then find the real leak (written warranty of performance). At that he decided to really find the leak which was at a pinhole leak at the dryer.
Unlikley to be so many coils leaking and the arcing at the electrostatic filter is very much more likley to be between the charged electrode and the ground electrode, whic is fairly normal. In any case the leak test (any of several types) would be able to show it up.

(I am not a HVAC contractor, did not sleep at a Holiday Inn Express last night, nor play one on TV. I do, however, oversee maintainance on a whole bunch of units in a very harsh environment and have done so for many years. I also have certification and enough training to be dangerous and enough sence to calla good company for service)

[fenian]

I had a Trane XL16i, variable speed air handler and Perfect Fit EAC installed late Nov. 2004. Since then the evap coil has had to be replaced every year since 2006 - a total of 4 times. The last time it was replaced a few months ago the tech said the evap coil was not level and condensation was dripping on the EAC causing an arcing leading to a small leak in the evap coil. Well it has been 2 months and we are now hearing the arcing noise again. Sometimes it sounds like a machine gun! Has anyone experienced this issue or have any ideas on why this is happening? I am concerned this arcing is damaging our EAC as well. Fortunately we have a 10 yr P&L contract.

Also, I recently had a PM and the tech showed me some (small amount) of mold/mildew around the wiring in the top section of the air handler. He tried to sell me a UV light but I am holding off on this. I think the mold/mildew is attributed to the coil going bad so often and not removing moisture from the air system properly. Again any thoughts/ideas would be appreciated.

is that dirt in the eac? and someone else will have to answer this... how does arcing cause a leak in the evap. coil and not play havok with the board.

[fenian]

the more i think about this the more questions keep arising. i gotta see a picture of that set-up. is the eac horizontal right under the coil? I never work with heat pumps so forgive me on this but i never realized there would be condensation in heat mode.

[dabolts]

One or more of the coils could have been misdiagnoced,not knocking your servicer,most brands says a significant number of coils returned test fine.Have they checked the refrigerant lines ,between the indoor and outdoor unit,for leaks?

I've heard there was an issue with the new all aluminum coils,do you know if yours is aluminum tubing?This was a mfg. issue and solved now,but some coils are still out there.

Mold/mildew in that area could be from a restrictive return duct system,causing condesate water to blow off the coil.Shouldn't be coming from the return air with your filter,if it's working and cleaned often.

Just some ideas,no conclusions.

Thanks for your response. They have used a leak detector each time and conclude the leak is always in the coil. I can't say for sure if they checked the whole refrigerant line but would hope they did since this is a reoccuring issue.

The coil is copper.

[dabolts]

Tell them you want a coated coil as a replacement this time. That is what give you the best shot at not having a leak. Trane will know exactly what you are talking about. You are blessed that you have a 10 year warranty, but you are paying for the electrical usage when has leaked down.

Thanks for your response. I recently read about the coated coils and will request this if the coil needs replacing again. And yes, it would be nice to have lower electric bills every month as this is why I invested in this higher seer rated system.

[dabolts]

Mold in the blower compartment of an air handler isn't unsual. It's in the cold air supply. Usually able to just wipe it off unless it builds up over the years and turns nasty.

As for water leak, could be issues with the coil "raining" and needs to be washed. Could be they are not putting a large enough trap in the drain line.

Thanks for your response. The amount of mold/mildew was minor. I did mention to the tech doing the p.m. that I heard a hissing noise in the top portion of the air handler as it sounded like it was not sealed properly. He ran foil tape around all joints.

[dabolts]

It is very possible that you have a small leak elsewhere and you are receiving a BS diagnosis. I have seen this a number of times.
The last time the tech said that the coil was leaking and needed to be replaced and I asked him to show me the spot with his leak tester. He himmed and hawed and said is was spread out all ovet the coil.
At that I told hin that I would approve the replacement, but if it still leaked he would refund the cost and then find the real leak (written warranty of performance). At that he decided to really find the leak which was at a pinhole leak at the dryer.
Unlikley to be so many coils leaking and the arcing at the electrostatic filter is very much more likley to be between the charged electrode and the ground electrode, whic is fairly normal. In any case the leak test (any of several types) would be able to show it up.

(I am not a HVAC contractor, did not sleep at a Holiday Inn Express last night, nor play one on TV. I do, however, oversee maintainance on a whole bunch of units in a very harsh environment and have done so for many years. I also have certification and enough training to be dangerous and enough sence to calla good company for service)

Thanks for your response. There was definately some water dripping on the EAC as one grid has some water staining on it as does the pre-filter. I have seen the arcing first hand at night - quite a light show.

[dabolts]

is that dirt in the eac? and someone else will have to answer this... how does arcing cause a leak in the evap. coil and not play havok with the board.

Thanks for your response. The EAC is well maintained as I clean the pre-filter monthly and the grids every 3 months or less depending on how they look when I check the pre-filter. I also have a p.m. done every 6 months.

[dabolts]

the more i think about this the more questions keep arising. i gotta see a picture of that set-up. is the eac horizontal right under the coil? I never work with heat pumps so forgive me on this but i never realized there would be condensation in heat mode.

The EAC is horizontally mounted under the coil. We only have the problem when the A/C is running. I can tell you that the air handler is not completely level which is a concern I pointed out when it was installed and was told it is OK. As a result the last tech to install a new coil had to gerry-rig the coil to puch it forward into a more level position which he felt would correct the on-going coil problem.

[fenian]

The EAC is horizontally mounted under the coil. We only have the problem when the A/C is running. I can tell you that the air handler is not completely level which is a concern I pointed out when it was installed and was told it is OK. As a result the last tech to install a new coil had to gerry-rig the coil to puch it forward into a more level position which he felt would correct the on-going coil problem.

can you post a picture of the unit?
the alleged arcing to cause a leak is still throwing me off. It doesn't make sense.
Plus i'm not sure an eac should be horizontally mounted, especially under something that in its lifetime has a reasonable possibility of icing over (if you forget to change the filter, etc). don't take my word on that as i'd have to pull out some manuals to be sure.
I'm always nervous when a tech has to gerry-rig anything. The problem should be corrected. Not half-assed addressed then walked away from.