Boiler condensate colour

RonV

The boilers have not been cleaned with TSP. As far as I know they have only been brushed and vacuumed, no cleaning chemicals used, and not since the fall of 2005 in any case.

A small leak is possible, but I have not monitored to detect this. I don't see any signs of make-up water entering the system, but to be honest I would have to be quite lucky to see such signs as the quantities would be low. If there is a leak, this might be consistent with my impression that I see the colour after the boiler fires cold rather than when it runs continuously hot. I mean that i didn't see this colour in the condensate during the coldest part of the season, but things are warmer now and the boiler isn't running as often. Perhaps there is a leak when cold but not when hot.

The boiler room is absolutely clean (spotless) and receives burning air from the outside vent as well as from heated/finished basement air through an open boiler-room door. The plant material theory is interesting. We have many big trees near the house and the big cedars rain down very heavy clouds of pollen this time of year. There is a small chance of Maple seeds getting in there too, but seems unlikely.

Is there any easy way to detect a water leak?

RonV

colour of boiler condensate

My heating system is operating just fine since built 5 years ago, but I'm a bit concerned about the colour of condensate from one of my two boilers. This year, boiler #2 has been operating as the primary and #1 only runs during heavy load. The condensate from #2 is clear and colorless much of the time, as seen in the little loop of clear tubing coming from the SAF-T-VENT flue (its a forced draft type). But occasionally it goes dark grey-green. If I empty the tubing and refill the trap with a bit of clear water and leave it then the water stays clear for anywhere from a day to a few weeks and then suddenly its dark again. This colour reminds me of corroded copper. Boiler #1 has always been clear and colourless, but this colour in #2 has been there since built I think. Is this something to be concerned about?

background details:
boilers are Slant Fin Victory 150, natural gas

Lurkin' Murkin'

If the 2nd boiler is off for long periods of time, and that is the one that gets the grey-green color in the condensate, I would imagine that it is an algea of some sort. Maybe more steady running, like boiler #1 does, prevents this from forming? Are the vent systems the same type, length, and configuration?

LarryC

Algae growth in condensate line

Perhaps you may have phosphates in the condesate line. Did you or someone else clean the boiler with TSP? Perhaps there is a small leak in boiler #2? The area where boiler #2 draws its air, is it a laundry space or gardening supply storage area? Perhaps laundry soap or fertilizer is making its way into the furnace? Or, is it possible that plant material is finding its way back down the flue and resting where the condesate runs over it on its way out the trap.

RonV

Boiler #2 has done all of the steady running this season and the colour continues despite that. The vents are different in that #2 is longer (at about 13 feet vs boiler #1 at about 9 feet) and the #2 vent exits the side of the house directly above the #1 vent (separation is about one foot or so). I am suspicious that the #2 vent is getting dust and pollen blown back into the outlet more so than #1 but both outlets have solid top/perforated bottom sides so the wind would really have to blowing to do this.

Lurkin' Murkin'

Sorry, I mixed up the boilers #1 and #2. I don't know much about what conditions that algea likes, but assume that you are concerned with the trap clogging over time with it? You say (below) that the combustion air comes from both an outside vent and the room the boiler is in? This is not possible, it can only come from the outside if there is air intake piping installed. Does each vent terminal have a vent outlet and an air intake built into one unit? If so, then one must not be located above the other, or flue gas will be drawn into the air intake of the upper terminal, from the vent outlet of the lower terminal. This can cause CO formation and damage to the boiler components. If the vent outlets are separate from the air intakes, then it is O.K. to have vents located one above the other. Hope this helped better.