LW cutoff related trouble. Bolier water problem?

/_2

Boiler shut down, LWC alternating green / red, water level normal in sight glass. 10 minutes later LWC went green, boiler kicked on and short fired (less than 3 minutes (Very Fast)) to reach .75 psi. Psi dropped slowly. refired with same results. steam not reaching radiators.
I turned pressure up to 2 lbs temporarily. Boiler fired for 20 minutes without significant water level drop in sight glass???, but all radiators charged and condensate began returning to feed tank. Boiler never reached 1.5 psi. During all of this the LWC was alternating between solid green and green/red simultaneous, but the boiler continued to fire.
Finally, the level in the sight glass dropped very fast(no leak in tanks, no siphoning) and the feed pump kicked in -- adding much more water than normal. boiler kicked on for 2 minutes before LWC cut in and started alternating red/green again, bringing me back to the beginning (water level normal in sight glass). LWC 802 model, brand new.

recent changes: Since November 15th, I have had a boiler cleaning company come in and, at their suggestion, add chemicals 3 x per week to scavenge O2, remove scale and condition water.

The boiler is a 1 million BTU Peerless in a 30,000 ft. building with a 2 pipe system. Before the season I repiped the feed tank to remove a master water leg, allowing the system to work great at .5 psi (until the start of December.)

I installed 2" drains at bottoms of outer tanks, but have not blown down through them yet. Should I try to purge boiler through them?(my cleaning guy says it is not necessary yet). Could these troubles be related to excess loose scale?

I need to replace my traps, but could they be causing any of this?

System is off now.
Any ideas?

[Deleted User]

Sounds like

too much chemical. I would blow down the boiler & tank. Several times. Stop the chemical. Re-fill w/ fresh water. If problem clears up in a few days w/ no chemical - find another company.

/_2

Chemicals could confuse the LWC and cause the psi problems?

RonWHC

Yes.

PH above 10.5 can cause foaming & priming. Dissolved solids don't help either. Read what McDonnell says about boiler chemicals in their instructions. Whenever we see what you describe, & chemicals are in the system, we commence rigorous blowdowns. In extreme cases, we drain the boiler, tank, any wet returns, & refill w/ fresh water.

Boiler chems are great when done right. When done w/ a heavy hand or pump, particularly on steam, they can be a royal pain in the a _ _.

/_2

When you said priming and foaming you hit a chord -- that is exactly what has been happening. Funny, when my chemical guy told me he wanted to see the PH at 12 I was going to mention that Dan Holohan recommends PH no higher than 9, but I thought I shouldn't question a chemist. Lesson learned. I will post again after I purge my system. Thank you.

/_2

Dissolved solids

MM lit says that probe indicates short by flashing green / red. Dissolved solids allowing too much conductivity?! AHA! It is all making sense now.