Humidifiers and Dehumidifiers - Humidifier 1042-LH not performing as expected!

My GeneralAire 1042-LH is not performing as expected; I’m not getting the desired humidity level in the house (house is about 1900sq. ft, and 1042 is suited for it). I had it installed (by a professional) on the return side. The humidistat is also installed on the return plenum and is functioning correctly. The humidity is too low. I’ve turned the humidistat to its highest level, and so the water is running all the time through the evaporator pad. But the humidity still can’t get above 32% (the outside temperature is about 5 deg. F (or -15 deg. C). The unit is 3 yrs old, and was functioning properly up to the point when I had an AC installed (but I’m not sure if this is the cause of the problem). I have maintained the unit myself (including the filter in the water line, the distributor trough, and replaced the evaporator pad, etc.); everything seems fine. Is there anything I can do (such as re-install the unit on the supply side, etc.) to improve the performance of the unit?

Remove the bypass cut that cut into the supply side and see if opening has been blocked by the coil, and see if you got good air flow out of that opening.

If all is good, then is the water on hot or cold water?

How often does your furnace run an hour and avg run time each time?

Thanks Jay11J. I have already done that few weeks ago. The coil is not blocking the bypass opening. Also there is good air flow to the bypass. The water is on the cold side, and the furnace runs on average 3 to 4 times per hour for 5 to 10 minutes each time. In case you’re wondering, there is water at the exit of the humidifier. BUT it is very cold here in Ottawa. When it warms up a bit, the RH seems to go a bit higher to 35% level...

Like Jay is saying could the new coil screw up the air flow to the humidifier?????

The 5 to 10 min run time is not really long enough on a good cold day.

Do you run your fan 24/7?

I am experiencing the same problem with my unit ( Model 1042LH too). However in my case the unit was installed in the supply plenum with the bypass in the air return line. From the posts on this forum and reading the installation manual, I found out that my humidistat was installed in the wrong spot - downstream from the bypass line and was reading the humidity from the bypass. I relocated the humidistat about half hour ago and have turned my fan on. Will leave the fan on for more than an hour and them check for any improvements.

It may take more than a few hours if the house is pretty dry.. may take a few days.

But good that you saw it was set up wrong in the first place.

I let the fun run continuously for 4 hrs yesterday, no difference: humidity level still stuck at 32%. Also I have raised the thermostat setting by one degree to let the furnace run a bit longer and more frequently, still the same issue. Given that the size of my home is small (relative to the capacity of the humidifier), I still don’t understand the lack of good performance for this unit. Even in warmer days, though the RH in the house is raised by 2 to 3% at the highest humidistat setting, the performance of the unit is not acceptable. Last year when noticed the same problem, I let the fun run for 24 hrs for two days, and the RH went up only by 1% (outside temperature was more or less constant). I still have two more things to do (for verification purposes) and after that, if nothing significant becomes obvious, I’ll give up on this unit. First thing, I’ll verify if the water flow out of the unit is 3.5 gall./hr (or 1 qt. in 5 minutes), as given in the specs. Second thing, check the accuracy of my hand-held digital reader for humidity (if anybody needs to know how to calibrate such a device, I’ll pass to you the info.). Concerning the latter, I did actually compare readings from the digital meter and the humidistat of the humidifier, and they are very close.

Thats a bypass unit you sure you are getting a good air flow through it?????

I am experiencing the same problem with my unit ( Model 1042LH too). However in my case the unit was installed in the supply plenum with the bypass in the air return line. From the posts on this forum and reading the installation manual, I found out that my humidistat was installed in the wrong spot - downstream from the bypass line and was reading the humidity from the bypass. I relocated the humidistat about half hour ago and have turned my fan on. Will leave the fan on for more than an hour and them check for any improvements.

I decided to replace the Evaporator Pad yesterday. This afternoon, I checked the humidity around the house - its up between 40 -47% ! Two days ago, I could not get higher than 32 %. So relocating the humidistat and perhaps replacing the pad also helped. I had the humidistat set to 45 - I'll turn it down to 40 later today.

Thats a bypass unit you sure you are getting a good air flow through it?????

I have never measured the air flow in the bypass (I do not have the means to check it), but I think it is ok. On saturday, I measured the water flow at the drain to check if the flow is within the one given in the manual. Well, I was getting three times higher rate of flow! I checked the "Troubleshooting" section in the manual, and it suggests replacing the orifice fitting (which meters the flow delivered to the distributor), since it indicates that it is enlarged (delivering much more flow than needed). But the manual does not say if too much water flow will cause lower humidity or not? My intuition tells me too much water flow may actually cause too much humidity? Am I wrong in my assumption?

The air will pick up the R/H it can get . No mater what the flow is

As I mentioned in my previous posting, I found out that too much water was going through the humidifier due to enlarged metering orifice. I called the manufacturer and they were nice enough to send me a free new orifice fitting. I installed the orifice fitting and Voila the problem disappeared. Therefore, It does matter if too much flow goes through the evaporator pad!