Thermostat settings for Broomell System

BRIANJ

Thanks to the advice from all the Wallies my Broomell two pipe steam system is running pretty well but I have some new questions particuarly about the thermostat and vaporstat.

For background, my 94 year old house is about 2400 sqft of living space, full unfinished basement and attic. Basement is poured concrete and attic is not insulated, only insulation is between the second floor and the attic, only other insulation is provided by aluminum siding from the 50's which I hope to remove someday. Just had a Peerless 63-06 boiler installed, insulated Mains and risers, cleaned boiler 3 times with "Super Washing Soda"(sodium carbonate not bi-carbonate) and installed 2 Gorton #2 vents at end of main. Radiators start getting hot after 15 minutes from cold start. Still getting rusty water from old returns. Honeyweel CT36 Thermostat and Honeywell L608A-1046 Vaporstat (cut-in at 2oz cut-out at 6oz).

I set the thermostat to 64 degrees during the night(11:00PM) and 69 for morning(5:45AM) and back to 64 for when we go to work.

Here's the question:
Because there's no insulation and the walls get cold it takes a while to make up the 5 degrees. After the boiler has been running for a while and building pressure the vaporstat cuts out at 6oz., the thermostat is still asking for heat, the Vaporstat resets itself and the boiler comes back on. The system is filling with steam and the Gorton's are closed, pressure is building and it's almost like short cycling as the vaporstat turns itself off again. Is there a thermostat out there for Vapor systems that will give the boiler say 5 minutes before restarting? This would allow the steam in the radiators to condense for a while and the heat to transfer to the rooms. My installer (a wonderful and knowledgeable man) suggests setting the night temperature at say 67 degrees. This way the boiler wouldn't cycle so much in the morning and evening and would be just as efficient.

Would appreciate any thoughts on this subject? Has anyone experienced a similar situation?

Thanks to all for your wonderful advice. Brian

Jamie Hall

Mine's a Hoffmann

but basically the same principle -- and an astonishingly similar set up -- except that I was able to insulate some of the roof, and the basement is dry laid stone (1770, more or less...)

I use a Honeywell programmable thermostat, set for steam (one cycle per hour). 58 night, 63 early morning, 63 (weekdays) or 68 (weekends) day, 68 evening. The vapourstat is set at 8oz/1 oz.

Yes, the vapourstat cycles at the end of the recoveries, which I kind of expect and live with, but a longer delay wouldn't change the heat much. The steam is still getting to the radiators, even at the 1 oz, and as soon as enough has condensed to bring it down to 1 oz, off she goes again. No cycling when just maintaining temperature.

I have found that if I set the recovery rise to 4 degrees instead of 5, it doesn't cycle (well, maybe once).

It's kind of a balancing act... I don't know of a way to get a longer delay. My concern there would be the boiler would need a bit of time to begin making steam again (when it is cycling, that's not true) so I'm not really sure what you would gain.

BRIANJ

Broomell thermostat/Vaporstat

Jamie,

What model # on the Honeywell thermostat you're using. Sounds like it has more features than mine. Thanks, Brian

hvacfreak

I wish

I wish I had an exotic vapor system ( 1 pipe oil here ). I'd have a JCI or Seimens program running 24/7 controlling multiple or modulating boiler ( s ). Residential controls ( yes ALL OF THEM ) are not where they should be. Imagine a Bromell , with a modulating gas boiler and a PID control system...I'm thinking AWESOME...but maybe someone has already tried this ?

http://en.wikipedia.org/wiki/PID_controller

Vermonter

Vaporstat settings and thermostat control

Just a humble HO opinion but it may help you out;

Set your vaporstat for 4 oz. cut-in and 10 oz. cut-out. That's what "The Lost Art" recommends.

I looked at the manual for your thermostat online and it looks interesting. The manual doesn't mention the minimum cycle time that it sends to the boiler. I personally use an AUBE TH148-LE-P that has similar features. It has worked wonderfully for me and will never tell the boiler "on" for less than 3 minutes.

I replaced all the air valves in my house, just didn't trust them.

I'm also working on replacing all the radiator supply valves. Many of them leaked between the spud and the valve and dripped (for years in some cases I'm sure) on the hardwood floors. Turns out that I lost a huge amount of steam through them and THAT accounted for the rapid pressure drop between cut-out and cut-in more than anything else.

I've got 2 or 3 more to do and that has solved several problems: the leaking, the pressure drop, they don't make any noise any more, I lose almost zero water from the system overall, and now I can actually turn the radiators off! The old ones had long since lost the gasket inside that made the seal nice and tight.

BRIANJ

Thermostat/Vaporstat settings for Broomell

HVAC you brought back some old memories.

I think the control manufacturers have missed the boat for residential units. Twenty-seven years ago I was given the responsibility of maintaining our computer system a Prime 350. Not knowing anything about computers they sent me to two weeks of school on how to do back-ups, formatting drives and systems operations and I was ready to go. The biggest problem was that the air conditioner would often fail. It was a 5 ton unit and when it failed the disk drives were ofter damaged. These were the big disk packs that looked like LP records and stored a hefty 50 meg each. They should have sent me to air conditioning school.

Back then there was a company that made a programmable controller called a RAMACS. They also had a speech synthesizer. I had the technician from Prime Computer isolate the on/off wire to the drives (from a harness with 64 wires) and then bought a $15 thermostat. Now, whenever the air conditioner would break down and the room temperature went to 85 the thermostat would drop from HI which would be detected by the RAMACS which would signal the computer to turn off the hard drives and kick off the synthesizer which would call 3 people at home (my boss first) to notify them that there was a heat condition and the system was shut down. Total cost about $1,300. If I could put that together there must be some company out there that can create an efficient and cost effective unit for residential heating or cooling systems. But the first one has to be for two pipe vapor. Brian

Jamie Hall

memories

cheer up guys. The heating system in my establishment originally had an HB Smith boiler darn near as big as the house. Coal fired. As the pressure rose, there was a neat little doo-dad which closed the intake damper in proportion. All mechanical. Worked fine, though I suspect the efficiency left something to be desired!

As you all say, wouldn't it be wonderful if someone could a) come up with an oil burner (mine's oil -- no natural gas anywhyer nearby) which could be turned down automatically by, say 50%, and then a nice simple pressure sensitive control to keep it running at a boiler pressure of perhaps 4 oz.

Dreams...