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MasterCool Evap Cooler problems - float valve

betsycam's Avatar

Join Date: Dec 2012
Posts: 4

09-15-13, 03:31 PM   #1  
MasterCool Evap Cooler problems - float valve

We bought a house that is 22 years old, and the MC swamp cooler on the roof is as old as the house. I can't even read the model number info on the label, and we have no owner's manual.

We'd been having problems with it not blowing cold. DH and I went up on the roof and found that the pipe with the holes for the water to come out were clogged with scale, so we white-vinegared it and cleaned it up.

However, after we cranked it up again, it still wasn't blowing cold! So, today I went back up and found that the pump wasn't running! While I was monkeying around, I lifted the float and water started gushing out, even when I dropped the float back into the water. I can't seem to figure out how to readjust the float so the valve will shut off when the tray is full of enough water! Did I break it or is there a way to fix that?!! It's hard to reach without disassembling panels or removing the 8" pad.

Meanwhile, I did remove the pump and it was clogged with gunk, so I pressure-washed it and put it back in, and this time it worked and the water squirted out of the holes no problem. Now I just have to get that float situation taken care of! I backed the water flow off as best as I could for now. Help!

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PJmax's Avatar
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Join Date: Oct 2012
Posts: 42,486

09-15-13, 09:30 PM   #2  
Welcome to the forums.

I'm not exactly familiar with your unit although I know you have an issue with your fill valve.

When you pick up the valve the water should stop coming out.
When you push it down the water should come out.

There should be some type of float that floats on top of the water and controls the water flow. It sounds like maybe the float has a hole in it and has filled with water.

I actually found a pretty good site with step by step instructions in how to replace the valve.
How To Replace A Swamp Cooler Float Valve

betsycam's Avatar

Join Date: Dec 2012
Posts: 4

09-16-13, 06:13 PM   #3  
Thank you for that, Pjmax!

sammy37's Avatar

Join Date: Feb 2009
Posts: 201

09-17-13, 08:04 AM   #4  
The float is broke. Those float valves need to be changed every two to three years as a small portion of it corrodes and it does exactly as you describe.

A float valve is only around 6 bucks and on that unit you dont have to remove anything except the side panel on the cooler to change it.

The pump needs to be replaced also. Once they start locking up like that, its only a matter of time before they lock up permanently. Pumps are around 25 bucks.

betsycam's Avatar

Join Date: Dec 2012
Posts: 4

09-17-13, 09:14 AM   #5  
Thanks, Sammy37 - are these items things I can buy at a Lowes/Home Depot or do I have to order them (ie. MasterCool brand)?

Gunguy45's Avatar
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Join Date: Dec 2007
Posts: 20,655

09-17-13, 09:29 AM   #6  
Lowes/HD/ local hardware stores should all have them. It's almost end of the season (in my area) so the choices may be limited.

For the valve...IMO... you should look for the brass valves. My plastic one only lasted 1 year.

"I sometimes wonder how some people ever made it to adulthood..."

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