Old Building, New (programmable) T-Stat for Hot Water System?

mrgem

I am one of the owners of a 4-unit, 1906 historic condo building that has some very vexing heating problems.

The building is heated by an old natural-gas-fired hot water boiler that sends heat to 4 cast-iron original radiators in each of the units as well as a couple in the common areas. Each radiator has a control valve that regulates the amount of hot water let into the radiator. Many of the control valves are over 100 years old and are frozen in either the open or closed position -- or somewhere between the two extremes.

The building has no air conditioning.

We had the system gone through last winter by a boiler/heating technician and one of his suggestions (and actions) was to replace the fancy programmable T-stat with a simpler non-programmable unit that featured what he referred to as an "anticipator.' He said that older hot water boiler systems don't work well with programmable T-stats.

Since it has starting getting colder, we've had complaints that while some units are getting too much heat, others aren't getting enough. I suspect it is due to frozen control valves (that are the property of the individual unit owners -- since they are within the walls of the unit). The owners of the affected units are resisting replacing their valves because of the expense involved.

Some of our owners are now blaming the simpler T-stats and think we should go back to a programmable unit.

Your thoughts on the subject?

nicholas bonham-carter

When the thermostat was changed was it still in its original location? That particular programable model may not have been the best choice for your hot water system, however many modern thermostats are. I would recommend a Honeywell Visionpro, with remote sensor. The main control could be locked up in the boiler room, and the sensor mounted in the appropriate location. Temperature setbacks of less than 24 hours duration should be not be used. If you have many people changing the thermostat then the comfort level of the building will drop. Make sure all the units have similar accurate digital thermometers, for reporting purposes. Fuel economy could be improved with the addition of OutDoor Reset (ODR), which would vary the temperature of the water in the loop based on the outdoor air temperature.
The valves can be fixed without changing the valves, by loosening the packing nuts and working the spindle free. Retighten the packing nut when done. Those valves are only to be used for balancing, and not for frequent alterations of flow.--NBC

nicholas bonham-carter

Also some thoughts on the ownership of the radiators within the units. These are part of the system as a whole, all of which should be designated as a common element, a percentage of which total maintainence is charged to each individual owner-like the roof, or drains. No individual should be able to make any modifications to the radiators without permission from the condo regime.--NBC

Paul48

Just a thought.......I don't think there can be anything worse than, not being able to be comfortable in your own home. For those not currently affected....I wonder how they would feel if that situation changes, mid-winter?

gennady

It is distribution problem. Not a thermostat issue. Just get these control valves fixed and set them according heat requirements of each room.

SWEI

If you could post a few photos of the boiler along with the associated pipes, pumps, and wiring, we may be able to help.

I suspect this system might benefit from a bit more than a thermostat change.

icesailor

Remember, Old thermostats with "Heat Anticipators" work differently than modern thermostats that "Anticipate" through how many times the thermostat is supposed "cycle" in an hour.

"NEW" Thermostats aren't always a good solution for old systems unless understood.

If all the units in the Condo have control valve issues as you describe, it should be an association issue where every valve gets replaced and thermostats to run them. And an assessment is paid by the members. Are they "zone valves" or actual thermostatic zone valves? There's a difference.

Can you post pictures of what they look like? You'd be surprised at what can be repaired that someone might say that they can't be repaired and fixed.

mrgem

Apologize for the slow response. Have been out of town.
First, thanks to all who've weighed in.
To answer/clarify: There is a single T-stat (in a hallway) for the entire building. It was not moved. There are no zone valves in the regular sense. The entire building is a single zone. Each condo unit has multiple radiators -- each radiator with its own mechanical valve... as was typical setup for 100+ year-old building. By opening or closing the valve -- you control how much hot water gets into the radiator and the amount of heat it radiates. Some, but not all of the valves at the radiators are frozen. Those that are still working -- seem to do their job just fine, though.
On responsibility for maintenance: According to the building's HOA covenants and rules: any repairs/replacements to this system -- since it requires a licensed tech and/or a permit -- must be approved by the HOA. The covenants also outline the fact that despite the radiators' tie in to the building's mechanical systems - they are owned by the individual unit owner -- because they are within the walls of the unit. Just like a toilet or an electric range -- they belong to the homeowner.
All of this acknowledged, during the last year, we have had 2 boiler repair firms give us bids on updating the valves in the system and both have warned us that breaking open 100-year-old pipes could have major impact -- and could lead to tearing into walls, floors and ceilings at great expense -- if leaks occur. They will not be responsible if replacing valves in a unit leads to damage to the building and other units. It is kind of a tricky situation.
So getting back to my original question... The residents are convinced that the T-stat is responsible for the poor performance and are demanding that it be replaced and/or moved. Our regular boiler contractor says -- keep it simple. A heat-only T-stat that includes an anticipator is what he recommends. He likes Honeywell, so I have researched model T8775A -- a round digital unit that is for low-voltage controls. In order to confirm this T-stat's suitability for the application, I've called Honeywell's tech line. They are, simply put, useless. They recommended a couple of 120/240v units that are for electric heat. They clearly don't know what they are talking about. That is why I am looking for help here.
Thanks again for all the feedback, and thanks in advance for your advice!

nicholas bonham-carter

Old valves can be repaired/loosened up as I have said. The packing can stick to the spindle, and prevent its rotation-until the packing nut is loosened, and the spindle worked a bit back and forth. A deep well socket should be used so the resultant torque can be balanced with your free hand. If that does not work then the bonnet of the valve can be unscrewed and then put into a vice for working the valve loose.
All the valves must work in the system. Allow 15-20 minutes for unsticking each radiator valve, and then a couple of hours for balancing the system. Finally, remove all the handles, and store in a safe place to prevent the owners from altering the settings.
Modern thermostats probably do not have the old form of anticipator, with a small heating strip to trick the thermostat into feeling more heat than there is.
Is the location of the thermostat in an area where there is a radiator? It would be best to use the visionpro with remote sensor located in a north room on an inner wall. 4 sensors can be wired to average the temperature in different locations.--NBC

Paul48

I was thinking along the same lines. A thermostat with an anticipator might help the folks that are too hot, but not the folks that are too cold. Trying to use a single thermostat, and hoping to keep everyone comfortable is going to be nearly impossible.

nicholas bonham-carter

Grenady has nailed this problem-imbalance of the flow in the system, due to the tampered, and now frozen valves.
Fix the valves, balance the flows, and everyone will have the same amount of warmth.
Don't get sold on a more sophisticated control, such as a Heatimer, or Tekmar, as they require a system in perfect balance, and will make things worse on an unbalanced system.
Just to reiterate: fix the valves, and then use them to balance the system. You can make these valve work yourselves, with the proper tools!
Invite all your members to visit this website, and read what our advice has been.
The lawyer who drew up the original agreements should be drawn, and quartered for not putting all the radiators into a common element, as they are part of a system, whose individual parts must be maintained as a group, like any building walls, roof, or hallways.--NBC

mrgem

OK...Back again. Did not realize that I must activate the star on the original post in order to be notified of additional posts.

I really appreciate the info regarding rebuilding the existing valves. Our boiler guy never suggested that. He gave us a shocking price on replacing all of them. Furthermore, he told us that should he break a water line while replacing a valve, he could not be responsible for any damage that might cause. The conversation ended there.

One of our owners approached another plumbing and heating guy about replacing valves -- and he told her he would not touch the job. Too risky with 100-year-old pipes he said. So now, everyone is gun shy about touching the old valves.

Perhaps we should be looking for another heating contractor?

I understand everyone's concern about ownership of the radiators and the need to keep people from fiddling with their radiators once they are set up right, but that is the way the boilerplate language in the Condo documents reads.

It is very straightforward about who owns what: If it is inside the walls of a unit, it is your property. Within the walls or beneath the floors - it is common property.

Think about a toilet. It is connected to common systems (supply, drain, vents), but it belongs to the homeowner. The declaration and bylaw documents treat radiators like a sink or a toilet.

There's not much that can be done about that Changing the ownership scheme would require an amendment to the Declaration/by laws, and that would be expensive (has to be amended by an attorney and re-filed with the state).
So, back to the heating problems...

We have started gathering temperature data on the heat in each unit and the common areas and one thing is clear -- the T-stat is located in an area whose temperature bears little relationship to the temps in the individual units. It is on the wall in a stairwell that leads to our basement. It is not below grade - but very close - and as a consequence, its temperature only varies by a few degrees throughout the day. So...We are looking for a better location. If we can find a common area whose temps are more representative, that should help.

The current T-stat is a very simple Honeywell unit that is not programable. A couple of owners have asked if a programable or even a "smart" T-stat would help, but I would like to see the basic heat function working before we start introducing yet more variables.

Again, thanks for all the feedback.

nicholas bonham-carter

I have steam pipes which date from 1885, and I would not hesitate to apply some intelligent force to them. In the case of your system, the pipes have been even less exposed to oxygen than mine. The valves are made of brass, which does not rust, and so working on the packing nuts will not twist off the pipes and break them.
This is not a job for some ham-fisted plumber, as the valves, once free to turn, must be adjusted to give an equal flow to each radiator.--NBC