Condensate Return Pump Problem?

Brian_78

I have a seized condensate pump motor on my system and I had a pro take a look at what it would take to repair it. As he was checking out my system he noticed that the condensate pump and boiler are two separate mechanism. Meaning, the pump is turned on by the float in the tank and hence sends water back to the boiler. According to Dan’s book, "we got steam heat," this is exactly what the condensates job is...return the condensate back to the boiler.

The repair man is telling me that since my boiler is equipped with an automatic water feeder, and an independent condensate pump, there is a potential for the boiler to overfill.  His concern is that when the system is on and steam is being made, the automatic fill will add water to the boiler. Then when the condensate finally returns back to the boiler it will overfill it. His solution was to either pipe the automatic filler through the condensate tank, or wire some kind of switch from the boiler to the pump which tells it when to turn on.

Is this a real concern? If so what will it take to fix the problem and how much of an investment is it going to take?  

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Jamie Hall

and read on...

Your tech. is, to a certain extent, correct.  Note the comments on condensate return pumps vs. boiler feed pumps in "The Lost Art..." if you have it.  A condensate feed pump really doesn't care how much water is in the boiler -- the float trips and the pump pumps, regardless.  A boiler feed pump, on the other hand, senses the water level in the boiler, and pumps when the boiler needs water -- assuming there is water to pump.



If condensate is slow returning, and you have an automatic feeder, a condensate return pump can over fill the boiler.  Since yours apparently hasn't, this may not be a problem, however.



Beyond that, I don't feel qualified to comment...

Steamhead

My first question is

do you really need the condensate pump?



Many condensate and boiler-feed pumps are installed where they are not needed. If the condensate can return to the boiler by gravity in a reasonable amount of time, it doesn't need help from a pump. And as you've seen, condensate pumps have moving parts that can fail.



Have a real Steam Man look at this system. Try the Find a Professional page of this site.

Brian_78

Finding a Pro

I have tried the link and have posted previously for help in my area. Both attempts have failed. I am located in Syracuse, NY. Know anyone?



The home is on the larger size (3000+ sq. ft.) and according to Dans book I do believe my system needs the pump. I have less than 2 ft. between the water line and the lowest steam trap.



Anymore advice/direction would be greatly appreciated.

Jamie Hall

Steamhead has

as usual a very good point: you may not need a condensate return pump at all.  Your system isn't all that big -- the building for which I am the super is a museum, and has over 7,000 square feet heated on 3 floors plus the basement.  And no return pump.  It is, however, a vapour system which can make a difference.



Two feet is a little slight between the lowest trap (is it on a radiator?) and the water line, however.  One tends to wonder a little just what that trap is doing.  That doesn't mean it can't work that way without a pump, but to do so you would have to be absolutely religious about keeping the pressure down to avoid flooding that trap.



Do you have The Lost Art, or just We've got steam heat?  If you don't have The Lost Art, you should get it and study it with great care -- and then study your system with great care.  Even if you can find a good steam pro. (which would be the best thing) such study can help.  If you can't, you are going to have to become the expert, and help your plumber or whoever out yourself.  Such study can do that, too.

The Steam Whisperer (Formerly Boilerpro)

I agree with Steamhead

That 2 foot dimension is equal to about 2 psi of pressure.  I have had very few systems that needed that kind of pressure to operate properly.  Most will run on vapor pressures...8 ounces or much less( one I recorded fully heating the systems at 0.4 ounces).   At 8 ounces that minimum dimension drops to a little more than 14 inches (18 to 20 to be safe),.

find out what pressure you need to run the system, and then you can go from there.  Nearly all the condensate pumps or feed pumps that I come across in anything but large buildings have been unnecessary and when the opportunity comes I remove them.

Boilerpro

Jamie Hall

Listen

to Steamhead and Boilerpro -- they're about the best in the business.  But you will need to be really accurate on your pressure -- I (and I venture to say they) will recommend that you use a vaporstat, not a pressuretrol, to control the pressure.  Then get rid of the condensate pump and see how she goes.

Brian_78

How to determine the correct pressure

Jamie I’m curious to know what pressures you are running on your system? My system is set at 2 psi cut in and uncertain of the cut out at this point. And in fact it is a two pipe vapor system. The traps that are two feet above the water line are the F&T Traps on the return lines, they appear to be the original traps and hopefully have not been relocated or tampered with. My home also has three floors plus radiators in the basement. 

 

I’m wondering what pressure I should run my system at. Boilerpro brings up an interesting point…if my pressures were around .5 psi then I probably would not need the condensate pump at all. But I’m not sure what pressure I should run my system at? The “pro” that looked at my system suggested I run it at 4 psi? This is exactly the kind of knucklehead Dan told me to stay away from! I guess I should just turn the pressures down and see what happens.

 

I have only read “We Got Steam Heat,” I have the “The Lost Art” on order.    

gerry gill

I side with Steamhead

in that if the condensate can make it back to the condensate tank, it sure the heck can make it a few feet further to the boiler..you really have to have someone determine if you really need that condensate tank..i'm betting no, unless someone modified piping..

Jamie Hall

Now you've got three

of the top men -- I see Gerry has chimed in on the same chorus!



In answer to your question on my system: I use a Vaporstat.  Cutout is 9 ounces per square inch, and the differential (subtractive) is 7.5 ounces per square inch, so the cutin is 1.5 ounces per square inch.  It's a Hoffman equipped vapour system, and runs fine!



Try that -- I'll be you like it!

The Steam Whisperer (Formerly Boilerpro)

Jamie's got it

If you have a vapor system, I believe universally they never needed more than 8 ounces of pressure.   You'll need a vaporstat to be able to control that low, but for starters crank down the pressuretrol as low as it can go.  The boiler in the little picture is in a vapor system that had been running at multiple pounds of pressure.



Boilerpro