Found an Iron Fireman SelecTemp System today

Steamhead

This house is going on the market soon and the home inspector suggested we look it over. We're so glad he did!

As far as I can tell, this 19th century farm house was renovated in the mid-1950s (we found a 1954 date inside a toilet tank in that part of the house) and the SelecTemp was installed around that time. All but one of the original fan-coil units have been replaced by units with electrically driven fans, as seen in the pictures. For those not familiar, the original one is in the second pic- it is not hooked up at the moment.

A 1964 addition is "heated" with forced air.

Steamhead

In the boiler room, we find a Weil-McLain SGO-5 with a Weil-McLain QB burner. It had a plugged pigtail, which we replaced. There are two Pressuretrols on that pigtail, but since Code does not require redundant controls on this size boiler in Maryland, we didn't put on a second pigtail. The SGO can accept a secondary low-water cutoff by using a remote probe in the lower try-cock tapping.

The riser from the boiler goes into what I believe is some sort of steam separator. I've never seen one like it. After that, it goes thru what looks like a pressure reducing valve which is leaking. Question for SelectTemp Gurus like @gerry gill- Is this PRV still needed? If so, any recommendation for what to replace it with? Also, are there supposed to be traps on the original fan-coil units?

Steamhead

The first pic of these two is one of the F&T traps on the steam mains. The dip in the discharge piping looks original.

Two of the fan-coil units are located in the basement, so a condensate transfer pump was installed to handle the return water. This Hoffman unit is relatively recent. For some reason, a previous installer located a 101A-24V here instead of at the boiler, running it into the tank and reversing the float switch action so it would operate the feeder, while the pump was controlled by the low-water cutoff. In effect, they tried to use this dinky little tank as a boiler-feed rather than a condensate-return tank, which resulted in water overflowing the tank for years and years. We'll have to pull the tank out to get at the switch mechanism to fix this.

More later!

SWEI

Steamhead said:

All but one of the original fan-coil units have been replaced by units with electrically driven fans

I'd love to hear the story about why those were replaced. Ouch.

DanHolohan

Great find, Steamhead! I'd love to grab some of those pics for Lost Art Revisited.

JUGHNE

The end of main F&T trap with the copper plumbing trap on discharge before air vent. How does that work or does it??

So were the original fans steam driven? IIRC I read something about them, but can't find it now.

ttekushan_3

Nice find, @Steamhead. I think the PRV was there to maintain constant pressure despite varying demand. This kept the turbines' speed consistent and output correct. I suppose it could also have some steam drying effect. They were pretty explicit on the importance of dry steam.

In the absence of the steam driven unit heaters and in the presence of good near boiler piping, I don't think the PRV is necessary at all. I know Gerry doesn't use them.

The unit heater's trap was part of the individual modulating thermostat. The trap acted on the inlet valve. Both increasing room temp and a steam saturated heater core could close the trap. As the return from the heater core reached steam temperature, it throttled the inlet. That heater core is an extremely high density brass affair. The output on those was impressive. The one you pictured is good for 18,000 BTU max. They came in 6K, 12K, and 18K BTU models. Very compact, too.

@SWEI, the bearings, seals, and cores were all prone to failure. The last one I saw operating correctly still had good bearings and seals but the core was leaking. It was something to behold as it modulated. Except for the leak, of course.

Those look like Turbonics heaters. They wound up with the rights to the SelecTemp system.

Steamhead

DanHolohan said:

Great find, Steamhead! I'd love to grab some of those pics for Lost Art Revisited.

Grab away. If you want higher resolution than what's here let me know.

bob_46

ttekushan, I only worked on one of these systems, certainly not an expert, and I thought the turbine speed would modulate with the t-stat.

Steamhead

For those interested, I found the SelecTemp manual. Gerry Gill had posted it in an earlier thread. I reposted it here.

Turns out the end-of-main traps were supposed to be float-only- no thermostatic element. We'll have to check this when we go back.

@ttekushan , you were right about why the PRV is there.

The boiler feed-water setup shown in the manual is interesting, to say the least. Now I have an idea of what they were trying to duplicate when they replaced the pump on this job. They definitely did not want feed water going directly into the boiler, and they wanted a way to treat the water if needed and also to monitor how much feed water was going into the boiler. Nowadays we'd use a Hydrolevel VXT or a small water meter for the latter function.

JUGHNE

So this is vented like a 2 pipe rad with air vent on rad. Wet trapped cond return only. The end of main float trap would keep steam out of the return??

Steamhead

The air vent on the rad is only used where the return cannot be pitched down so it doesn't trap water.

GreenGene

My dad used to install Iron Fireman equipment, and we worked on Timken and GE's, just brought back a flood gate of memories.

Not all of them pleasant, cleaning an Iron Fireman boiler was no fun at all.

DanHolohan

Tell us about it, Gene.

GreenGene

All you have to do is completely dismantle it, we had one in our house, eventually I converted it to a Beckett burner, it was still there when my mom sold the house 20 years ago.

Interesting design, efficient for the time.

GreenGene

it was this model, got the pic from hvachacks

some hvac company in the midwest is using the name and logo

http://www.iron-fireman.com/

DanHolohan

Thanks!

RayWohlfarth

Wow so cool I have two old Iron Fireman Ashtrays from when I sold their burners. My son just found out they are worth money and I told him they were his inheritence