Why is replacing a thermostat so DIFFICULT??

I live in a Condo that has a shared heating\cooling system. It's pretty simple how it works. In the summer, they turn on ONLY the cooling system, so no heat. The cooling works by running cooled water through pipes that run through a radiator in each condo unit. The radiator cool air is then served out to the rooms by a large forced air fan.

The exact opposite happens in the winter, only heat is pumped. We have to then move a switch on the thermostat to the HEAT setting, and presto.

My thermostat is a White-Rodgers 1A10-651 LIGHT DUTY Line Voltage.
Line Voltage, SPDT Thermostat, 36°F to 90°F Range, 1.5°F Differential, Setpoint Locking Option, Range Limiting Option, 8 AMP at 120 VAC, 4 AMP at240/277 VAC,

The Owners Manual is here

http://www.white-rodgers.com/pdfs/04...Cat_pg_030.pdf

The current Thermostat is installed with both the red and blue wires on the back spliced together (since they share the same radiator system).

My need is to get a PROGRAMMABLE thermostat to replace this.

Why in the world am I having such difficulties? All the thermostat companies I call say they don't make a model that will work.

Can someone please help me out? If I can find a solution, I can possibly sell it to all the units in our association (over 400). Any product managers out there?

Mucho Thanks in advance.

 

I live in a Condo that has a shared heating\cooling system. It's pretty simple how it works. In the summer, they turn on ONLY the cooling system, so no heat. The cooling works by running cooled water through pipes that run through a radiator in each condo unit. The radiator cool air is then served out to the rooms by a large forced air fan.

The exact opposite happens in the winter, only heat is pumped. We have to then move a switch on the thermostat to the HEAT setting, and presto.

My thermostat is a White-Rodgers 1A10-651 LIGHT DUTY Line Voltage, SPDT Thermostat, 36°F to 90°F Range, 1.5°F Differential, Setpoint Locking Option, Range Limiting Option, 8 AMP at 120 VAC, 4 AMP at240/277 VAC,

The Owners Manual is here

http://www.white-rodgers.com/pdfs/04...Cat_pg_030.pdf

The current Thermostat is installed with both the red and blue wires on the back spliced together (since they share the same radiator system).

My need is to get a PROGRAMMABLE thermostat to replace this.

Why in the world am I having such difficulties? All the thermostat companies I call say they don't make a model that will work.

Can someone please help me out? If I can find a solution, I can possibly sell it to all the units in our association (over 400). Any product managers out there?

Mucho Thanks in advance.

 

Is the heating/cooling effected by circulating air thru ducts, or by circulating hot/cool water thru "base-board" convectors?

 

We need more info: Are the red and blue wires you refer to coming out of the wall or out of the thermostat connecting to a single wire in the wall? Is there another wire in the wall that connects to the thermostat? Is there a wire in the wall that doesn't connect to the thermostat? Are these wires large like would be used to wire 120V outlets or small like would be used to wire a door bell? What do they connect to on the other side? The fan unit, or a control box by the fan unit? If they're small wires and they connect to a box near the fan, can you open the box (be careful, there's at least 120v in there) and find a transformer where one of them connects? If so, are there 2 terminals on the transformer where you might be able to measure the voltage with a voltage meter?

The thermostat is controlling a fan (and possibly a water solenoid) via either a low voltage relay or a direct line voltage connection. Either situation would work with the mechanical thermostat you have, but we need to know exactly what's there to figure out what type of programmable thermostat, if any will work.

Doug M.

 

Is this what you're looking for?? http://yourhome.honeywell.com/Consum...ge/Default.htm

 

Thanks for your responses patbaa and dougm,

The thermostat has 4 wires coming out of it. Green (Ground), Black (Line), Red and Blue (I guess referring to the heat and air conditioning switch respectively).

All wires are thick NM wires. It's on a 15 amp circuit, so it is line voltage. The Red and Blue are spliced together to the white one, and the black to the black (Green to ground). These then enter the utility closet via a #14 NM wire, and go into a....light switch (believe it or not) which I assume was put in there to easily cut the power off to the blower motor without having to make a trip to the breaker box. The connection then continues from the switch directly to a cylindrical GE blower motor. The air from this is forced through insulated ducts, then to vents in the ceiilings of all the rooms.

Understand that all that is being driven is the blower motor. Since all the units share the copper pipes which send in the hot and cold water (depending on season), I think this water is kept at a certain "on-demand" hot or cold temperature. When the thermostat in the condo unit has reached a user set low or high level, it kicks in the blower, which then draws air through a copper radiator like grill (with copper circulatory inlet and outlets)...thus providing the cool or hot air that gets circulated. I don't believe there is a solenoid that is actuated by the thermostat. I think it is always circulating throughout the closed system. Though I never thought of that setup. Looking at it, the wires all go straight into the blower motor. The condos are about 30 some years old I believe.

It seems like such a simple simon setup, making my search for a programmable, digital replacement seem hard to understand. Why can't I find them for this single task? Turn on the circuit when the temp reaches a certain level, then cut off the circuit, cutting off the blower motor.

The reason I'm looking for this is the entire condo setup (420 units) are all run this same way. So when everyone goes to work, the thermostats keep the places at a nice, unchangeable, wasteful temperature. Asking the users to turn down, then turn up when they get home is going to be too much to ask of them.

You can imagine what it is doing to our Condo fees.

Thanks again !

 

just be aware with the PROGRAMMABLE thermostat you might have to pull another wire the stat most likely uses 7wire or 8

 

pazure,

Something is not right.
There is no wiring diagram at your link but the black on the thermostat will likely be common.
Blue is normally the open on temp fall contacts, which would control cooling and the red would be open on temp rise which would be the heating side.
Having these wires twisted together make no sense at all.
I have not seen a high voltage set back thermostat that will do both heating and cooling.
It is normally done by using a 24 volt transformer, a low voltage set back thermostat and relays to control the high voltage part.

With a better description of how your system is set up we might be able to help.
I am familiar with condos and apt complexes and I mean no disrespect to anyone but it is very common for bldg managers to hire unqualified caretakers to do work they know nothing about.
It's a case of paying a mtc person $12.00/hr as opposed to a contractor at $60.00+/hr.

I may not understand something in your description but if things are messed up, you would do well by having your system checked out by a qualified contractor.

 

GregH,

First, thanks for merging my two posts. I tried mightily to figure out how to delete my original post placed in the wrong area. Tried hitting edit, but couldn't see any delete feature. Tried FAQ's. Nothing.

Second, thanks for responding to my plea.

I want to point out that the current system works fine right now. My thermostat isn't broken...just inefficient. And because I've shown the initiative, I've been tasked by the condo association with figuring out a way to help us save on energy costs.

Not sure if I worded it properly in my initial post. The condo only has ONE of the two heating\cooling options on at a time. Coming up in October, they'll do a complete switch over to ONLY heating. The cold water that once ran through the pipes to cool the units will be replaced by very hot water, and the blower driven air passing over the radiator will now supply heat to the same apartments.

From that cutover point on until next spring, we will NOT have access to any sort of air conditioning. We can turn the 3 position (Cool - OFF - Heat) thermostat switch to Cool, but the only thing that happens is the blower kicks in, and we get hot air.

Strange I know, but doesn't this setup then explain the splicing of the red and blue wires together?

I'm not sure what much else I can do to describe the way the system works. I will work on a layperson's electrical diagram image, so maybe that will help. Will post tomorrow.

Mattison, I already gave thought to this unit, but isn't it 220V?, and how would it work to provide air conditioning? Doesn't it have to have a Hot - OFF- Cool capability like my current one does?

Thanks all. Good Night...

 

oops, I forgot you're cooling also. I'll check on one that will fill your needs.

 

pazure,

Does the thermostat turn off the fan when the temperature dial is turned to a higher number when in airconditioning?
I understand what you are saying about the blue and red wires being twisted together.
There wasn't a wiring diagram for the thermostat at your link but it is normal for a stat that is heat cool to use one of the wires, usually the blue for cooling and the other for heat.
having them twisted together will apply power at all times when in either heat or cool.
Turning the selector switch to off will open the circuit but moving the dial will not.

Is this how it operates now?
If not, what happens when you have the selector to either heat or cool and you move the dial?

 

GregH and Mattison,

Yes, it does exactly that, and it's not until you pointed this out that this is starting to make sense to me. And this explains why there needs to be a Cool and a Hot setting since they have opposite reactions. When set on COOL, there is a "threshold" that turns the blower on, and that is any temperature ABOVE the current dial setting. So turning the dial down when in "COOL" mode turns on the blower as it attempts to match the threshold temp to that new lower set level.

The dial, therefore, just sets this temperature threshold and closes the circuit when the ambient room temperature is met or exceeded. When the temperature is higher than the threshold (and the selector is set to COOL), the thermostat completes the circuit. When it is lower, it opens it, cutting off the blower.

This is where I am confused. You said

>> Turning the selector switch to off will open the circuit but moving the dial will not.

The dial does act as a circuit opener of sorts when the dial is turned to a high threshold temp....right? So if I want to open the circuit, I just turn the dial all the way up, and the thermostat will think I'm fine in 100 degree heat, so it won't cut on right?

If I set the switch to HEAT, the blower motor starts instantly, and will, I assume, run continuously since it is now looking to raise the temperature above the threshold, but all it is doing is cooling the room more and more (since only cool air can be pumped).

Sorry for all the dumb questions.

So is this now where the Single Pole Double Throw (SPDT) spec comes into play? When all is said and done, am I looking for a line-level, SPDT, Heat - Off - Cool digital, programmable thermostat?

I can't say enough how much I appreciate your help. I'm a computer expert and will be trying to pay back some of this generosity in the Computer section of this site.

 

Nope. The heat/cool switch controls which trip applies power. When in heating mode, power will only be applied by the red wire and only when the temp goes below the setting. In cool mode power will only be applied by the blue wire and only when the temp goes above the setting. It works.

I was really hoping this would turn out to be a low voltage system, but... The problem is that line voltage cooling thermostats, especially programmable ones, are not common, or may not exist at all. I haven't found one yet... Also, most line voltage programmable thermostats need a neutral connection which this setup does not have (functionally you could use the ground, but legally you couldn't and it wouldn't be safe).

Not that we couldn't think outside the box and make something work (convert everything to low voltage with relays...), but honestly, it probably wouldn't save what it would cost. I think you'd find that after a few weeks, most of the residents would simply place their thermostats in manual mode and go on as they were before. I've dealt with condo HOA's so I understand the difficulty of the issue, but they really would be better off looking into updating to modern equipment - separate systems in each unit. Either that or find a way to meter each unit's HVAC use and bill for it so everyone has a reason to care. Most will find that turning the temp up and down as needed really isn't all that hard if it saves them money.

Doug M.

 

Pazure since you have such a large quantity of work I am sure that your local contractors would probably be very interested in finding you a suitable replacement programmable unit almost all major manufacturers will have what you need it is a matter of picking out the most economical and the one you think your tenants would actually use as doug mentioned sometimes it is hard to convince renters of the value of taking pains to save something that they consider is a entitlement to them for paying rent some might actually prop open doors and windows and turn heat or coolon full blast just for spite some are just great human beings LOL I would call in a few contractors and maybe have some different units installed for a test then once EVERYONE AGREES you canhave them all changed out to the one that proves to be acceptable.

 

Think we're starting to go in circles...

Doug M.

 

Well it's good to know I'm not the only one confused here .

Perhaps a layout diag would help. It's not the greatest, and I think I've got all the connections right.

http://www.solisearch.net/ims/pic.ph...jL3s0&i=208695

 

Dont know if you can get by with it here. But have put controls on the boiler temp to cut it back in the day time. Also some motels has a outdoor tstat to go to cool or heat for a row of units and how they face. Then lots of time the guy that works the boiler controls the water temp not the blowers
I cant see how a programmable tstat on the fan will help you here "if I have this right" Id say a 24V tstat with a relay for the fan and a solenoid on the water line to the water coil


my .02cents ED

 

Ed is right in that the solution will be found in making changes to the whole system rather that at the thermostat.
This is why it would take a heating pro to look into this, even if it means going over your current maintanance people's head(s).


As far as your stat goes is that if the switch inside the stat were a spdt type it would not switch anything. The red and blue leads would be closed to the black lead all the time.
If it is switching then you will have two sp switches that have a deadband between them so that only one will close the cct at a time.
To see if this is so just slowly turn the control untill it opens then continue to turn and see what happens.

 

It's looking more and more like I will have to get a pro in on the job. I thought that at least I'd come here first to see if there was an easy solution.

I have since found a wiring installation instructions for the thermostat that is currently working. It shows how an internal schematic of the stat (page 2), and different scenarios on how to install it.

http://www.white-rodgers.com/pdfs/in.../0037-3911.pdf

Look on the second page. I think my setup is a combination of what they call the "Fan Coil System" and Heating-Cooling Fan-Coil System using two or more stats. The latter solution has a "Manual Changeover" which is what we have. Replace this with the "Fan Coil Systems" Outdoor air Automatic changeover S.P.D.T. Thermostat, and you have my setup.

Does this help my situation any, or am I still stuck contacting a pro and being told that the entire heating-cooling solution has to be changed?

Thanks all!

 

True, but the heat/cool switch disables input from the opposite contacts so this isn't the case. When in "heat" position the blue wire is opened and when in "cool", the red...

I thought about that too Ed, but if, worst case, all the units were unable to meet demand due to the lower/higher (summer) water temp, they would all run constantly and probably use more energy than they do now. It would also mean that residents who work off-schedules might not be able to maintain comfort levels in their units when needed.

Exactly. All the units could probably be changed over to a low voltage thermostat system with new wiring, and programmable thermostats for around 5 or 6 hundred dollars (guestimate) plus labor that might save a couple hundred a month on the HOA utility bill, but for a few hundred more each unit could be converted to a mini split system and the HOA utility bill eliminated. The system that exists now was great 30 years ago when utility costs were low and it's inherent waste was tolerable. It is not at all practical in a residential setting today.

One other thought: The 30 year old cooler/boiler unit is surly itself inefficient by today's standards. I think Ed covered this in part, but today's systems use computer controls to adjust water temp and distribution and save energy. Just replacing the existing cooler/boiler unit might provide more savings than setback thermostats and this savings would not be dependant on resident’s actions.

Doug M.

 

DougM,

Fantastic advice, especially about the inefficiencies of this old design and utility costs.

I had actually thought about a semi-elegant solution that WOULD work, but would be pretty demanding of users. It would work by replacing the switch in my layout with a Digital Timer. This timer would essentially open the circuit at user programmable times (when they go away on vacation or to work).

http://www.intermatic.com/?action=prod&pid=9045

Unfortunately, those who come home early from work would need a simple way to bypass the timer. This is cumbersome.

The **Ouch** in my title refers to the fact that they recently assessed us all a huge one time fee of ~$2,000 to pay for a new Air Conditioning Main Unit (or Heating unit, I can't remember now) that had broken down. That amount times the number of units is almost a million bucks.

I wonder if they even considered getting a pro in to reconsider the current setup, or if they just figured that since the unit was broken down, they had to replace it.

I know the Building manager, and he's a nice guy, but from the looks of it, he may have dropped the ball on this one.

 

AW yes the cost of it all. The best way we go now is say like 3 unit chillers .Put in for the whole load So #1 is like on all the time if load picks up then #2 kicks in to help. # 3 then is stand by. This way you can pull one to work on if it goes down.and still have the other 2 to carry the load. Doing that a lot here now. Same way for heat.

ED

 

Big OUCH! That alone would probably have covered installation of individual heating and cooling in all the units. HOA's are notorious for running poor businesses. Equipment repair and replacement should have been anticipated and there should have been money in savings to cover the expense. Smart businesses manage these funds with investments to make the most of their money... When was the last time you had an outside audit? On top of that, there should be someone in place with enough expertise to anticipate need and research all the options before a crisis occurs that removes all the options (like the one you had...). Anyhow, we're way out of the scope of this forum...

Timers were another thought of mine too, but they would completely eliminate all cooling and heating in the unit at certain times which is not desirable. In some climates it might even be dangerous. One frozen pipe could cause a catastrophic loss.

My thoughts are leaning back toward trying to find a device to install between the control box and the fan that simply collects run time. Then bill each unit by amount of usage. Dues could be lowered some to compensate residents for their new expense and the utility costs would always be covered. Most condos and apartments here are now metering and billing every utility at every unit. With resource costs being what they are today, it's the only way they can continue to survive.

Doug M.

 

http://www.grainger.com/Grainger/pro...mId=1613554157
Here's a possible run time collector. Sweet and simple - Hire an electrician to mount one on the fan control box at each unit and connect it to the hot wire for the fan. Put a big plastic locking cover over the whole thing and you're done. Someone would have to read all the meters and prepare bills which can often be contracted out to a property management company as an individual service if it can't be done internally. This cost is washed by the savings to the HOA. All the numbers have to be put down on paper and balanced so that everything is covered (what I do for a living...). All tolled, each resident will probably end up paying more each month, but the HOA won't ever have to worry about it again and everyone will learn not to waste.

Doug M.

 

Final Stabs at a Solution

So when all is said and done, is the consensus here that a line voltage thermostatic device theoretically cannot be manufactured that would do what I need?

My initial solution to the problem was to convert to millivolts using a step-down transformer to power the unit, but how would you then send a start signal to the 120V blower fan? I'm by no means an electrician, and am just speaking from my very limited knowledge of how stuff like this works, so perhaps this is completely wrong.

What would be the layout if I were to switch to a millivolt stat? This would probably be the least expensive method right?

Other Solutions

Well, we did have a reserve fund, but it wasn't enough to cover the cost of this "unforseen" incident, so the assessment covered the cost, and some extra to put into a new reserve fund.

Not sure how the investments portion is going. I guess I should ask more pointed questions at the next board meeting.

More sound advice. Your solution would certainly work. Perhaps even give the unit owners a "switch if you want to" option. Those who switched over to the metered way would pay exactly what they used, and would thus be incentivized to make their condo units as efficient as possible. The remaining utility costs would then be pooled and shared by all those who haven't yet switched over. This would certainly light different sorts of heaters....under their butts to get switched over!

 

Not cannot be, but probably isn't. Actually, I think it probably is somewhere, but not readily and probably not for a residential environment.
There are packaged devices that do everything you need. Something like http://bestbuyheatingandaircondition...ategory_Code=R. Then the wiring would have to be changed. Add a good programmable thermostat and an electrician to install it all and you're at around $500 each unit.
Sure! Whatever gets you there. As units turn over they can be switched as well.

Doug M.

 

2 slip in wall unit heat pumps might do the job for each unit cost a lot less???????????

ED

 

Yet another good possibility.

Given that the HOA just spent a bundle on the existing system, I'm sure they're tapped out and will have to make the best of what's there for a while. It'll have to be depreciated out, hopefully on an accelerated schedule, but that'll give them time to plan and allocate funds for new systems. I go through this with customers every day. I often have to present no win numbers to those who didn't bring us in soon enough and made unfortunate decisions on their own. What I'm getting at is that we can brain storm this and come up with all kinds of ideas, but it really all gets back to what was said by some of the other posters: A good HVAC pro should be able to analyze the complex and propose all the solutions with pros, cons and numbers to compare. Y'all are already in somewhat over your heads so getting a pro in before spending any more money would be very prudent.

Doug M.

 

I would like to go to the board and talk them into doing what you suggest. Do you know anyone (or can you recommend anyone) you trust who works out of the Northern Virginia Area?

 

Afraid you're a bit out of my stomping ground (and I know more of the bad ones than the good ones here.) Maybe some others on this forum can, within the posting rules, provide some leeds. Yellow pages, internet and The Better Business Bureau are great resources. In your case you might get 2 or 3 different pros to look at things and see what they come up with. Good luck.

Doug M.

 

This forum cannot be used for getting leads but I can suggest you look in the phone book to find a company that specializes in commercial equipment.

Another thing I can suggest is that you hire a mechanical engineer to survey your system and offer recommendations.
This would cost several thousand dollars but you would have some assurance you would be doing the right thing.

 

Will do.

Thanks one final time you all for your amazing help!!

Peter