Heat Timer MPC Gold issues in 1 pipe steam multifamily coop

margaretnyc

Before I get to the problem, I need to provide a short history... I manage a 40-unit coop building in northern Manhattan that is 100 years old. We have a 1-pipe steam system powered by an HB Smith 28 series 12 section boiler installed in 2002 with Heat Timer MPC Gold controls. The system has worked very well for us until last November when an apartment on the top (5th) floor complained of no or very little heat. The super changed all the valves which made no difference. The only way the apartment would get heat was to put the boiler on bypass and heat the heck out of the whole building which obviously is not sustainable. Thinking it was a distribution issue, we hired a company to:
-install master vents at the end of each main in the basement
-install a new operating pressure control for the boiler
-vent the risers in each of the top floor apartments (2 per apartment) with Gorton D vents
-Install a Gorton D vent before the radiator shut off valve on each of the radiators in the 8 top floor apartments.
It was also recommended that we install Hoffman #40 vents and TRVs on ALL of the building's radiators. We chose to hold off on these measures due to cost and until we could see how the master and top floor venting performed. The results were dramatic. The problem apartment was now toasty and we were able to ease back the controls so our boiler was running less. Of course now that the problematic unit was getting heated, most of the other apartments were being overheated leading to open window syndrome.

We looked closer at our heat timer and realized that the indoor heating sensor is located in the boiler room on the wet return line! The manual states that this sensor should be installed on the last radiator in the system to get warm. Unfortunately we have overlooked this major oversight for MANY years and we need it corrected. Furthermore, the heat timer does not seem to be calibrated well which is no surprise since no one has really touched it since it was installed. I would really like to bring in an experienced controls/steam heat person who can install a new sensor for us and calibrate the Heat Timer which I believe is the missing piece to our solution. Any thoughts on all of the above or recommendations on NYC and environs companies or individuals are welcome. Thanks guys!

Warmly,
Margaret

Jamie Hall

At least you have heat...

There are a number of good folks right here on the wall who service your area -- use the "Find a Contractor" tab.

Steamhead

We just covered this topic, here:

https://forum.heatinghelp.com/discussion/165589/sarco-boiler-return-trap

This is a common problem with these control systems. Fortunately, it's not too hard to fix, and there are plenty of Steam Men in your area. Try the Find a Contractor page of this site- go here and follow the instructions:

https://heatinghelp.com/find-a-contractor/

the_donut

The best control system, installed and configured wrong, can lead to the worst performing systems. Sometimes a simple heat only thermostat installed in the coolest common area (not near a door) works best.

We had one building with a tekmar 261 that performed worse than a Honeywell heat only thermostat due to configuration issues. That being said, if configured right, they will save money and keep people comfortable. You just need someone familiar with the controls and the system attached to get it set up right.

This reminds me of audio engineering (something I do at church). You can have the best equipment, great vocals, excellent tracks from the band, but if you don’t mix it right, the music sounds terrible. Best of luck on the configuration and sounds like the stars of owners, tenants and maintenance willingness to tackle the issue are aligning for another system rescue.

nicholas bonham-carter

I suggest you move this post to “strictly steam” from now on, for more eyes to be on it. Possibly Erin, our moderator can assist with that.
How many storeys are in this building, and does it have an indoor temperature sensor for the control?
There are a number of steam experts who service the NYC area, posting here, who can fix this for you. If you want to vet them first after compiling a list from here, then search out their posts here to give you some prejudgement of their ability to diagnose problems, and communicate.
I believe these Heatimer, and Tekmar controls are capable of using the returns as a monitor for steam arrival, but they work only on well balanced systems. Ironically, many have been sold as a cure for excessive fuel consumption on large badly maintained systems, a task unfortunately beyond their ability to perform!
I suspect that your problems still lie in inadequate main venting, as the new main vents may not be large enough. Overpressure may also be at fault. You will probably find a lower fuel consumption, (sometimes dramatic), and greater comfort for all, after this, as your system when first installed, heated everyone evenly, or the installer would have been thrown in the river!
I don’t know if your system uses temperature setbacks which require the boiler to use extra gas to catch up in the morning, but this produces a situation where the lack of venting and an improper control make some people chilly. A constant lower temperature is always more comfortable and economical.
It would also be useful to determine what temperature determines “cold”. Some indoor outdoor/wireless thermometers will give you a reading of the highs and lows of the temperature in an apartment, without having to bother the occupants.—NBC

JohnNY

Hello MargaretNYC,
I install and service Heat-Timer systems often, as well as tekmar. Both controls still have some problems dealing with the weather during this time of year or what we call the "shoulder seasons", but as was mentioned earlier, a system has to be able to function well on its own before any control will bring it to that wonderful next level of efficiency and comfort. When I do a complete system evaluation of a building like yours, 40-units and the like, the problems with balance most often lie within changes made locally apartment-to-apartment. People change radiators, turn off valves, move walls, ignore broken windows, leave leaky air conditioners in the windows, etc. The system has to be looked at as a whole, then addressed in parts. It sounds like the pipes are well vented and you've made good upgrades to the controls. Now it's probably a room-by-room evaluation with a thermal imaging camera that'll get you to nirvana...or something somewhat acceptable, anyway.

As for the sensor, the truth is it can go on any pipe that produces a reasonably consistent surface temperature when the system is satisfied or filled with steam. It's not a perfect system and the variables far outnumber the constants. Don't beat yourself up for overlooking the *proper* placement of the system sensor.

nicholas bonham-carter

You will be in good hands with John, or any of the other NYC steam experts.
They will know how to measure the back-pressure of the system during the air venting phase, to see if your new main vents are really adequate for the volume of air which must be allowed to escape, before steam can travel to the radiators. These systems function best at very low pressures of ounces per square inch-less than needed to blow up a balloon!
They will also be able to tell if the boiler had been properly cleaned after its installation, removing the surface oils from the water, which can restrict steam production.
After making sure that all the radiators on each floor are receiving steam at the same time, they can diagnose any building envelope problems which may be making some people chilly.
The cost of this could be equal to the first few months fuel savings of next winter.--NBC

jumper

System was satisfactory for fifteen years and then went bad? Did vents stick closed?

nicholas bonham-carter

In these cases, the deterioration can happen over a period of time, and with changes of super, the system can become degraded so slowly that no one notices. They open windows, or put on more sweaters to compensate, because “hey it’s steam”. Finally a new family moves in who are not used to the old situation, and they say,”we’re cold/hot”.
When they finally get things working right, the other residents are amazed, and hopefully will say “hey it’s steam!!”—NBC

question

When things have been working for many years and something all of a sudden has gone wrong it usually means someone changed something. I would be curious as to what was the solution. Also I would of put larger vents on the risers to get the heat/ steam up faster. I would of used Gorton #2. They vent at a rate of 2.2 cfm at 3oz pressure , The D vents at .70 CFM at the same pressure. I would also vent the mains with Big mouth vents which are rated at 3.6 CFM @ 3 ozs. Getting the cold air out quickly from the mains and risers will help you balance the whole system.
I would also say it's time to upgrade the boiler controls. You should save at least 15% anually on your fuel bill with that alone.

ethicalpaul

I think it’s great that a building manager actually wants to improve things for the tenants rather than just shrugging and saying “well, it’s an old building!” As we hear so much here. Good on you!