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[jreimer]

Hi all,

Does anyone else have the problem of water expanding and overflowing out of the water level indicator on the Optimizer 250?  It seems that it's a poor design where the tube is sealed and the water expands more than the tube can hold.  I have to keep my water level below the tube so this doesn't occur.  This defeats the purpose of the water level indicator.

Anyone else have this problem or a solution?

Thanks!
James.

[slimjim]

You should only add water to your boiler when it is up to temp as the water in the tank heats up it expands and pushes out the vent then when you come back and the temp has gone down the water contracts bringing the water level down

[jreimer]

Jim, what you described works for the first heat/cool cycle.  Unfortunately this fill method still doesn't work after that.  As it cools, the water level drops below the bottom lip of the fill pipe.  Then it expands again as it heats up and the water level reaches the bottom lip of the fill pipe, then continues to expand as the boiler gets up to temp.  Because the boiler is sealed, the expanding volume of water in the entire tank pushes the water out of the fill pipe as the volume of the fill pipe is minimal compared to the volume in the tank. 

It's hard to explain, but hopefully I'm getting the point across.

It may be designed this way on purpose to pseudo-seal the boiler to outside air, but it doesn't account for the expansion of 240 gallons of water.  If you would set it to a 2 degree differential it may not do this, but anything more than a few degrees differential causes this to happen.

[yoderheating]

I've never looked at a P&M but that doesn't sound like a very good system. I guess you have to simply check the water level when its at the highest temps?

[martyinmi]

We have 3 250's in this area and none of us have ever had the issue you are describing.
We all made sure that our boilers were full after the first time they got up to temperature, and we've not added another drop since.
My guess would be that ball float attached to your level indicator somehow got cracked and is water logged.
The float extends down beyond the filler neck an inch or two into the boiler vessel. If it is water logged, it will give you a false reading and tell you that you are low when in fact you are not.

I run my boiler @ 190 on and 195 off, and once in a while I'll misjudge the load amount and not put in enough and my temperature will go down quite a bit, sometimes as much as 40 degrees, but I've never seen the fill level indicator move more than 1/4 to 1/2 inch.
I keep mine right at the half way mark, and the only time it has went down to the low mark was when I shut it down during the summer.

I keep a spare float on hand, but in two years of burning, none of the three of us have needed it.

Call the folks at P&M and see what they say. I'll wager it's the float, and they'll probably send you one for free if your boiler is new this year.

[willieG]

expansion of 250 gallons of water from 160 degrees to 180 degrees will be about 1/2 gallon

[jreimer]

Marty,  I'm wondering if my filler neck is too long or my float is too short.  My float does not extend past the filler neck, so to get a reading the water needs to be partially up the filler neck.  The filler neck is smaller than the expanded water and it pours out over the top.   I checked the float and it's not leaking.

I'll take a measurement of the filler neck length tonight and let you know what I find.

[martyinmi]

jreimer,
I'll bet that our filler necks are the same length.
I took the float assembly off and made a few measurements.
Underside of the cap to the end of the float is 15 1/2".
End of float to the top of the plastic rod (where the fill marker is) is 16 1/2".
Total length of threaded plastic rod with stop and float removed is 12 3/8".

[jreimer]

Hi Marty,

I finally measured my float and filler neck and it seems the float is the same length at 16 1/2".

A question for you is how long is your filler neck in the stove? 
Total filler neck tube length is 14"
Filler neck tube sticks out of the top of the stove 1 3/4".

Thanks,
James.

[slimjim]

I don't know why I did't think of this before but now that I have would you please check something for me. Take the cap off the fill neck and look down inside the pipe to the bottom of the pipe( if you need to drain some water out do so) but look on the side of the pipe at the bottom to see if there is a slit cut into the pipe to allow the air to escape from the water tank, I have seen this before on the 350 but not the 250. PM me if you don't understand what I am talking about, include your phone # and I will talk you through it. sorry for the brain cramp. Richard @ PM

[jreimer]

Hi Slim,

There is no slit cut.  This would explain why the air cannot escape and pushed the water out.  Maybe I can get a hole drilled into the side of the pipe to release the air?

[slimjim]

I just did one a couple of weeks ago, PM me with your phone # and I will explain what needs to happen or contact Brian and he could do the same. Sorry our screwup but is an easy fix, thank you for your patience.

[jreimer]

Just thought I would update this post with the fix to my problem.  P&M sent me instructions on how to drill a hole in the filler neck to relieve the pressure in the boiler as the water expanded.  Seems this was an issue with the design, or maybe my stove got a bum filler neck from the factory. I'm guessing all the new stoves have this resolved from the factory. 

[slimjim]

Thank you very much, I think it was one of those things where somebody missed a step in the process and nobody caught it, many thanks to those who brought it to our attention, problem solved.