Is it normal for water level in tube to go from 25% to 100% ?

sreja

I asked this before on a thread that i think was deleted because spammers were attacking it. But i never really got a clear answer to it so i'm asking it again.

I know that a severely bouncing water line is indication of dirty water.

What I am observing however is something different:

Water line at 25% or below when boiler is firing at 50% (2 psi or off).

And then water line goes right up to 100% top of glass when boiler is firing at 100% gas level (still 2 psi).

Is this normal or is this an indication of frothing/priming/surging dirty water? Inquiring minds really are desperate to know.

[peerless 211A08 boiler]

thanks in advance!
Is it normal for water level in tube to go from 25% to 100% ?

sreja

Does anyone have any advice for me on this?

it's literally the last issue i feel like i need to understand before i make my final most difficult decision about whether i need to insist on having a skimming connection retrofitted.

nicholas bonham-carter

bouncing waterline

boiling water contains steam bubbles whic increase its volume and lower its density so some bounce is inevitable.
frothy boiling magnifies the effect and leads to greater waterline movement.
have you performed the sightglass test?
this situation is further complicated by the automatic fill system.if that could be cut off for a day or so you could see more accurately what level was being maintained.
another factor may be the pressure which for experimentation should be tried at its lowest point on your system.the main vents on our 60 radiator 211-a system have removed all the air at 2-3 ounces. the vaporstat is set at 12 ounces.
it's only a matter of time before your boiler will need skimming following your most recent trap replacement.
if a catastropic failure were to occur because a 1-year-old boiler had been installed incorrectly,would there be any problem holding the installer responsible? therfore why not in the case of the "forgotten" [but required] skimming port?--nbc

sreja

Hi nicholas,

I actually wired in a little switch to let me turn off the automatic water feeder (based partly on your advice about it in the past).

Being able to turn it off is actually a great thing especially now that we have a malfunctioning condensate pump which sometimes floods -- and so this at least limits the damage when that happens since the boiler doesnt keep refilling with fresh water over and over again.

Regarding site glass -- i have done all the tests i know to do from Dan's books that i can do. I might try the boiling on a stove one next.

I just keep thinking that this 25% to 100% waterline behavior im seeing (which isnt the same as bouncing) is a big clue, but the fact that no one is replying telling me that i'm right seems to suggest that i'm wrong and that this is pretty normal behavior.

The reason i am obsessing about it is that if i was right it would be something really really easy to show the old contractor in terms of proof that the boiler needs skimming.