Vapor system - Illinois Heating Systems - Main Vent

jcwenger

1929 house, equipped with an Illinois Heat Retainor and Return Trap
(https://archive.org/details/IllinoisThermoModulatingSystemOfVaporHeatingIllinoisEngineeringCo._824/).

Each radiator has a thermostatic trap. The ends of the mains return back to the boiler room, and drop into the wet return, along with thermostatic traps venting into the dry returns, which feeds the Heat Retainor. (traps as air vents, p 238-239 TLAoSH)

Previous owners had the system running at 13 lbs. (Yes. I know.) Previous owners never did anything with the thermostatic traps, decades old undisturbed paint on them, they're all assumed to be shot. System works exactly like you'd expect it to when not maintained -- many dead cold radiators, no flow, water hammer, etc. It finished out the spring running at 3 lbs, which is as low as I can get the pressuretrols to go.

And finally, one (only one) radiator upstairs has a Hoffman #41 installed, and if it's closed (the vent has its own valve), then the system pressurizes to 4 psi, is air-bound, and nothing does anything.

1. So given that, my belief is that the heat retainor and/or the return trap may be clogged up or crusted up. Is this valid, or would it also get air-bound if all the thermostatic traps are shot?

I do firmly believe that the heat retainor and return trap have seen no maintenance in 20+ years. we have very hard water, and the boiler has a leaking seal, so the automatic water feed has been running once a week for who knows how many seasons, adding a fresh supply of new minerals.

2. Is there any information or advice on draining, maintaining, testing, or anything else with the old central vents? The link above states that the air vent is a metal-on-metal seat. Can they be disassembled and cleaned up?

3. Assuming it is bad, and If the valve can't be gotten into working order through draining and flushing and maybe if possible servicing, what are the next steps? Obviously there's no replacements available. If not able to be brought back into service, is there any option other than to convert the system to a 2-pipe (non-vaccuum) arrangement?

We've got a heating professional (Larger commercial heating contractor familiar with steam heat and who does quite a bit of old building residential steam) coming, but wanted to get a bit of community opinion to know the right kinds of questions to ask.

--Thanks,
Jason C. Wenger

Steamhead

@jcwenger , that Heat Retainer is, as you state, the only air vent in the system. I'm sure that's part of the problem. Before you take it apart, check the little vacuum check-valve under the dust cap on top of the Heat Retainer. If this check valve sticks, air can't vent.

Trap parts are available from Barnes & Jones or Tunstall. No need to completely replace the traps.

Where are you located?

jcwenger

@Steamhead, The Illinois Heating Company didn't get too creative in their distribution. Rockford, IL.

Yeah, I intend on getting the theromstatic trap parts replaced, not the whole trap.

Question was really about what to do with the central vent and the boiler return trap. Dan says, "Back out out of the room slowly without angering it" which doesn't help much if it's not working.

Jamie Hall

Who do you have coming? Can you get @The Steam Whisperer (Formerly Boilerpro) to come?

You'll have to get some sort of main vent or vent cluster working. Fortunately, that can be done -- it would be nice to keep all the original stuff, but if not you can go to a conventional vapour system without too much hassle.

mattmia2

The heat retainor looks to be more or less an f&t trap.

jcwenger

mattmia2 said:

The heat retainor looks to be more or less an f&t trap.

It's also the central vent.

Jamie Hall

jcwenger said:

mattmia2 said:

The heat retainor looks to be more or less an f&t trap.

It's also the central vent.

It may look like an F&T, but I doubt that it is -- particularly if it is serving as the main vent. F&Ts in theory can do some venting. In practice... not so much.

dopey27177

Before you start major work on the system, take apart all the major parts of the system, you will probably find a lot of dirt, possible collapsed float balls, hung up linkages all can be repaired. The vent valve most probably cleaned and made smooth again to be serviceable.

Of course this needs to be done with the customers permission.

Restoring the system to original or near original operating system will in the long run provide comfort and economical operation.

Make sure the customer is aware that there will be no short term pay back.

Jake