Condensate Pump Question

wildrage

First, I really appreciate all the help I've been getting from all of you. I'm going to shift gears and ask a different sort of steam question.

I have a Hoffman Watchman condensate pump in my setup. I have 2 series of steam traps - 1 right above the pump, and one about 15 feet away, that has a pipe run under a grate in the floor, back to the pump. I'm not sure the size, but I read that these hold at least 6 gallons, up to 14. I'm guessing mine is on the smaller side. There is copper piping that runs to the lower part of the boiler, spliced into where the auto water feed goes in.

I've read that there's a float in there, and the pump runs when it's full. I traced the only wire going to the pump, and it goes directly to the breaker box.

Here's my question. How the heck to I know when the boiler actually needs water? I'll see that it's running low (usually after a week or so), and I'll fill it up. For all I know, there's 5 gallons of water sitting in the condensate pump, and when the float triggers it, I have a situation where I have too much water in the system. It typically doesn't take my boiler out of the normal operating limits, but its annoying.

Is there any strategy here? I'm surprised that the pump isn't also hooked up to the low water switch - do people do that?

Steamhead took a look at my system and said that there's no reason for me to have a condensate pump (shoudl just be gravity), but I"m going to be in the market for a new boiler in the next few years, so am holding off.

Thanks,

Jim

Jamie Hall

First off, @Steamhead is right -- no surprise there. I doubt very much that you need a pump on that system. That said, since you have one, it should be controlled by the water level in the boiler, not the water level in the condensate tank. If that were the case, it would be a proper boiler feed pump, and wouldn't be a problem.

So. You have an auto feeder which presumably is turned on by a level sensor in the boiler (I also assume that you have a functioning low level cut off for the boiler at a lower level? I hope?). The thing to do is to rewire that so that it controls the pump from the condensate tank. Then when the water level in the boiler drops, it will happily feed from the condensate tank. Then take that float in the condensate tank, and use it to control the water feed, which is rerouted to go into the condensate tank, not the boiler. That way, when the water in the condensate tank is low it gets water fed to it. May take some replumbing as well as rewiring.

Has the additional advantage that cold water feed doesn't go direct to the boiler.

wildrage

@Jamie Hall

Yea, that makes sense. One thing I did notice...and maybe it's just a coincidence...when the water got low in the glass during a cycle, the condensate pump clicked on...but I can't find any sort of wire going to it. I see the wire going from the low water control to the water feed, but nothing going to the pump. The only wire I can see is the pump to the circuit breaker. I'm assuming it's just a coincidence that it clicked on.

I agree with the plumbing. Right now I have copper piping going from the condensate pump to the furnace, where it 's T'd into the auto water feed, with several check valves along the way.

Quick question - is it flat wrong not to be wired from the low water switch on the boiler, or is it just better to be wired that way?

The pump looks pretty ancient, but still works (for now). When i do get a new boiler, I will delete it from the system...as far as I'm concerned, another $1500 failure point.

Thanks for the quick response!

Jamie Hall

"Quick question - is it flat wrong not to be wired from the low water switch on the boiler, or is it just better to be wired that way?" No, it's not flat wrong -- there are lots of systems out there which have condensate feed pumps (controlled by the float in the condensate receiver) and automatic water feeders (controlled by the boiler water level. It is not, however, in my opinion the better of the two ways to do it. The boiler really doesn't care how much water is in the condensate tank, after all!

The only real disadvantage to a boiler feed pump arrangement is that the condensate tank may over fill on occasion, particularly if the condensate return is slow for some reason and the water feeder gets overambitious -- so you want to have an overflow running to somewhere where it won't hurt anything.

wildrage

@Jamie Hall Yea, I agree with you...it makes sense. Every once in a while the boiler is overfilled, and I'm assuming this is the culprit. There is a delay worked into the feeder, but if that float doesn't get tripped in that time frame, it won't work.

I think there's a big overflow coming out of the pump, pointing into a floor drain. Looks a bit like the emergency blow out from the boiler.

EBEBRATT-Ed

@Jamie Hall is correct it would be better if the condensate pump was controlled from the boiler. But your going to have to add a pump control on the boiler to do it. Otherwise you will trip low water cut off when the pump feeds.

However, it's going to cost you a bit to do all that work. If your going to install a new boiler and ditch the pump in the future I wouldn't bother doing all that work. Keep the boiler water line 1/2 a glass full. let the condensate pump do it's thing

Make sure you have a dependable low water cut-off that works.

Then if the water line holds as it should and the condensate pump is not overflowing your fine

Pumpguy

In order to avoid a starve-then-flood situation at the boiler, I would suggest you adjust the float switch on the condensate pump's tank to cycle at the absolute minimum range.

For this setup, both of the semi-circular stops on the float switch linkage dial should against the silver colored die cast pointer arm.

This will have the same effect as having a much smaller tank, and in a usual application could cause the pump to short cycle. In your situation, I don't think this would be a problem.

JUGHNE

You said you have two traps. One above the pump and one away that has a pipe that drops down under a grate. Does that one then go up into the cond pump. If so how does the air get out of that trapped return?
If it can't then I would put vents just before the trap to vent air out of that dry return. (assuming it is a 2 pipe system.)

Even if you get rid of the pump and still have this water trap you still need to vent air. IMO

wildrage

JUGHNE said:

You said you have two traps. One above the pump and one away that has a pipe that drops down under a grate. Does that one then go up into the cond pump. If so how does the air get out of that trapped return?
If it can't then I would put vents just before the trap to vent air out of that dry return. (assuming it is a 2 pipe system.)

Even if you get rid of the pump and still have this water trap you still need to vent air. IMO

There is a vent on the far-side trap, and it does run back to the condensate pump.

wildrage

@Pumpguy That sounds like a good idea. I think i'll screw around with it when I'm not depending on the Boiler as much as I am now. With the weather at 5 degrees at night, the last thing I need to do is fat-finger something or snap something off . I'm thinking March lol.

@EBEBRATT-Ed Yea, that's what I was thinking. Right now it's vaguely annoying, but not terrible. I ran into an issue this week because the water was a little below half glass, which is typically fine (because the pump will typically click on soon and replentish), however, with the really cold weather, the boiler has been running longer, and the low water cut off was tripping if the system didn't have enough time between cycles for the water to come back to the boiler. i waited an hour after the low water cut off to add water (so i wasn't adding it to a hot boiler), and by the time I got down there, it was back at half glass. I guess, for now atleast, I'm better off keeping it at 1/2 glass at minimum, and if it gets to 3/4, so be it. I had an issue with the autofeed sticking on about 2months ago, so I cut off water to that....so I've just been watching it closely.

wildrage

@Jamie Hall @Pumpguy @EBEBRATT-Ed

Ugh this is annoying. So even though the Boiler is 2 floors below, it is directly below the master bedroom. In the middle of the night, I heard what I thought was the auto water feed running (I have the valve shut, so it doesn't actually feed water). I ran downstairs, and low and behold, my water is at the bottom of the glass and triggering auto feed (but the valve is shut due to a prior flooding issue). I wait for the boiler to cool down, add water to about 5/8, then start it back up. I just went to check it now (a few hours later), and the water is near the top of the glass. I'm guessing the damn condensate pump is the culprit, although I could have sworn I heard it run before I added water. Could something else be amiss year? Like a slow return? I guess the good news is, I'm not losing much water at all.

The house is really big. I would venture to say that the furthest radiator is 150-200 feet away from the boiler, as the crow flies. 7,000 square feet, 3 stories, 15 foot ceilings, 250k btu boiler. With this cold weather (-5 at night to about 15 during the day), the boiler has been cycling about 30 mins, every 1-1.5 hours in between, running for about 8 hours of total call for heat a day. Could the boiler be starting back up before the condensate has enough time to make the 200 foot journey, enter the pump, trigger the float, and get back in?

Also, people talk alot about the minimum glass level...what about the maximum? Seems like my sweet spot is almost to the top of the glass...which gives me wiggle room with the condensate pump and the (possibly) slow returns.

Pumpguy

Besides the condensate pump's tank having too much volume and holding condensate rather than sending it to the boiler, the other possibility might be a non-functioning, or maybe even missing header- to -return equalizer line.

If/when the boiler stops making steam, the steam in the header condenses and shrinks in volume, causing a deep vacuum in the header. This induced vacuum holds condensate in the header, preventing it from flowing back to the condensate pump.

The attached files show the usual equalizer lines that should be part of the piping in a 2 pipe steam system, at least those that I am familiar with.

EBEBRATT-Ed

I would suspect .

Slow or plugged return line