Can I use a programmable thermostat with an oil furnace that circulates water?

replying to nestork , Buck wrote:

_______________
Awesome on all fronts - thank you all for all of the information. I feel confident that I now know what to do regarding both the thermostat AND bleeding the radiators... and how to do it!
Again, I appreciate all of the information, this has been exactly what I needed.
-- Buck
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The thing about hot water heat, unlike forced air...
with forced air you turn up the thermostat and instantly hot air blows .......
with hot water heating you turn up the thermostat, the boiler comes on and heat slowly moves thru the system....
given the slow cool down and slow heat up a setback thermostat may not save you much energy....
but if you turn it down much you may spend hours shivering.......
its your choice
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Bob Haller is correct; there are advantages and disadvantages in every kind of heating system out there.
If you can afford it, the heating system that I believe is the best available for a house is a "hybrid" system. That's where the run all the ducting the same way they would for a forced air system, but, instead of having a furnace with a heat exchanger, you have an "air handler", which is basically just a powerful blower that blows air through that ducting into the house. And, upstream of that air handler you have both a coil for heating and a coil for air conditioning. Hot water from a boiler flows through the heating coil during the winter and freon from the central air conditioner flows through the cooling coil during the summer. 1 hybrid system combines the climate
"controllability" of a forced air system with the 100+ year lifespan of a cast iron boiler.
The advantage of hot water heating systems is that they lend themselves well to "zoning", such as you would need in an apartment block, office building or shopping center. You can direct hot water with zone valves to go where you want, including reducing the heat to apartments or store fronts or floors of a building that are temporarily unoccupied while still having normal heat to those areas which are occupied. But, you can't add air conditioning to a hot water heating system like you can to a forced air system.
HOWEVER, for every heating system, the best way you save the MOST money is to turn down whatever kind of thermostat you have and put on a pair of long underwear and a sweater. Out great grandparents came from Europe and were given free land to occupy the plains states and provinces, and they had to endure winters with nothing more than a wood stove that tripled as a clothes dryer and residential heating system. And, they survived no less for wear by dressing for the cold. In my case, I once had a tenant come to me in the winter wearing nothing more than a pair of shorts and a pair of sandals, and telling me that he's cold in his apartment. I nearly killed the guy with a baseball bat.
--
nestork


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bob haller wrote:

Hi, New generation 'stats with brain works with this kinda situation in mind. That is why you tell the 'stat what kind of system you have on initial set up menu.
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some hot water systems can have have a thermostat control each radiator for easy zone control.......
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bob haller;3104204 Wrote: > some hot water systems can have have a thermostat control each radiator > for easy zone control.......
I think you're talking about Danfoss radiator valves.
You can use them on a radiator train, but you can't really use them for individual room control because they work by restricting the flow of hot water through the radiator. So, if you turn down the heat on an upstream Danfoss radiator valve, every radiator downstream of that one will be restricted to that temperature or less.
That is, how can you get a flow of 2 gallons per minute through a downstream radiator when a valve upstream of it is limiting the flow to 1 gallon per minute?
I've had experience with both Danfoss valves that don't require any power and Honeywell 24 VAC zone valves, and the Honeywell is definitely the way to go... more expensive, but well worth it in the long run.
--
nestork


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On Thursday, August 8, 2013 11:52:05 PM UTC-4, nestork wrote:

That's an interesting issue that I've never heard discussed before. I even recall seeing Richard Trethway on This Old House putting one in for a customer. But there was no discussion of what happens to the downstream radiators. These are widely used in Europe. What do they do? It would be easy to have a two port valve, where if the temp set is reached, the water goes out the second port that bypasses the radiator and sends it on it's way down the rest of the loop. But the ones I've seen, I don't recall it being anything other than a simple valve that blocks the flow of water. So, as you say, once it shuts off the water, all radiators further downs stream are screwed. So, how does this actually work?
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On 8/9/2013 7:47 AM, snipped-for-privacy@optonline.net wrote:

Far as I know radiators are connected in parallel. Baseboard heaters are connected in series (or series segments connected in parallel).
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On Friday, August 9, 2013 11:09:16 AM UTC-4, bud-- wrote:

I would think STEAM radiators would be connected in parallel, but hot water based ones? Why would they be connected any differently than baseboard ones?
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' snipped-for-privacy@optonline.net[_2_ Wrote: >

I don't know anything about steam heat.
Cast iron baseboard radiators that carry hot water will be connected in series within each apartment. They have to be because that apartment's thermostat controls the zone valve that allows hot water flow through the radiator train in that suite.
The radiator trains in every apartment are connected in parallel. They have to be so that each apartment can recieve heat independant of all the other apartments.
How would it be if the radiators in an apartment block were all connected in series so that all of the output from the primary pump would go through suite 1, then Suite 2, then Suite 3, and so on until you got to Suite 22. Suite 1 would get hot and so they'd turn their thermostat down and that would stop the flow through the entire building.
It's series connections within each apartment radiator train, and all the apartment radiator trains are all connected in parallel.
In a house, _one_would_expect_ that the radiators in each loop would be connected in series, and all the loops would be connected in parallel as Bud says cuz it only makes sense to do it that way.
However, it's only recently that zone valves became commonplace in houses. Until about 20 years ago, most houses simply had a gate valve on on all but the longest radiator loop. They used gate valves instead of globe valves because they offered less resistance to flow AND there were no internal parts (like washers and screws) that could come out and screw up the heating system. Those residential gate valves were called "balancing valves", and the whole idea was to close the gate valve on the shorter loops, thereby forcing more water flow through the longer radiator loops. The idea was to have the same amount of water flow through each radiator loop to provide for uniform heating throughout the house.
PROPER balancing valves will have pressure taps on both the upstream and downstram ends of the valve. They sell pressure gauges that allow you to connect a pressure gauge across the balancing valve to measure the pressure drop across it. You then open or close each balancing valve until you have the same pressure drop across all balancing valves, and that means there's the same hot water flow through each balancing valve for uniform heat distribution in a house. But, as I say, years ago the plumbing contractor would just use $4.99 gate valves and guestimate when the flow through each loop was about the same, and then put the new homeowner in charge of doing the fine tuning.
--
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On 8/9/2013 10:37 AM, snipped-for-privacy@optonline.net wrote:

The radiators in my house are connected in parallel. From what I have seen of the exposed piping in other houses, those houses were in parallel. Most (all?) radiators I have seen have balancing valves on them - multiple valves don't work so well if they are in series.
Radiators have a lot more thermal capacity than baseboards, and take far longer to heat up. In a series connection, the last radiator would just be starting to heat when the first one was hot.
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Everything I'm talking about refers to hot water heating.
I know squat about steam heat.
In hot water heating, all radiator loops in a house or commercial building will be connnected in parallel, and the radiators in each loop will all be connected in series.
You achieve uniform heat distribution throughout the house when the flow rate of hot water through each radiator loop is the same.
Since some radiator loops are shorter than others, it's common to compensate for their lower resistant to flow by installing balancing valves in those loops. The balancing valves can be partially closed to pinch off flow through the shorter loops, thereby increasing flow through the longer loops.
Balancing valves aren't needed when each radiator loop is controlled by a zone valve, as in the case of an apartment block. Radiator loops with zone valves maintain a comfortable temperature by having the zone valve controlled by it's own thermostat. It's only when you have one thermostat for multiple radiator loops that you need balancing valves to ensure uniform heat distribution throughout the house or commercial building.
The above is true for HOT WATER heating systems. I don't know anything about steam heating systems.
--
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On 8/10/2013 7:12 AM, nestork wrote:

Series segments are used with baseboard heat. I doubt you will ever see it for radiators.

All that assumes the baseboads are exactly matched to the heat loss in that room for the water flow rate. Differences in matching between segments can be equalized with valves.

With steam the major heat transfer is from steam condensing to water. The supply is steam and the return is water. Steam radiators have to be in parallel.
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wrote:

Not only that, but even when the heat was up for hours, if the radiators were in series, it's not like Xmas tree lights. The first radiator would emit a lot more heat than the 2nd which would emit more heat than the 3rd. I don't know numbers ,but say the water temp was 160 going into the first radiator, and 140 coming out. Then 140 going into the 2nd and 120 going out. And 120 going into the 3rd radiator. I wouldn't expect much heat from that one, or any beyond it.
In parallel, it would be 160 going into all of them and maybe 140 coming out. They could have a zone valve in the main pipe, before the pipe to each radiator split off, so the zone valve controlled a whole apartment.
The house I lived in in college had probably 15 hot-water radiators spread over 3 floors. My apartment in Brooklyn had steam, but it still had at least 5 radiators (the dining room radiator had been removed for some reason, but it got enough heat from the other rooms.)
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wrote:

That is, Xmas tree lights all glow at the same brightness, either because they are in parallel (and each bulb is designed for 110v), or because they are in series but each light has the same voltage drop, the sum of all of which is 110-120 volts. (If there are 24 bulbs, each is designed for about 5 volts.)
But hot water radiators in series are not like Xmas tree lights in series (or parallel) . For one thing, the water flow is all in one direction. There is no alternating water flow in a hot water furnace system, like there is AC current in your home's electrical system. So the hottest water gets to the first radiator in a series system. .

If two of these radiators were in the same room, it would be a little warmer on one end of the room compared to the other. But more likely, one radiator is in each room. The second room would not be as warm as the first and the third would be cooler than either.

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wrote:

One more difference. When electrical devices like light bulbs are in series, the same amount of electricity flows through each one, so if that is enough to light one bulb, it will light every identical bulb to the same degree. Because the flow of electricity is what does the work.
When hot water radiators are in series, the same amount of water flows through each one, but it's not the flow of water that does the worlk The water is there to transport heat, and even though the same amount of water flows through the second and third radiator, the amount of heat in that water is less and less, in each successive radiator.
It could be the flow of water that does the work. If a stream were routed to 3 flour mills in series, and the water fell from 160 feet above sea-level to 140 feet in the first one, from 140 to 120 feet in the second one, and from 120 to 100 feet in the third one, and each used the water wheel just as efficiiently, all three mills would get the same amount of energy and work out of the water. Buy that's not how hot water radiators work.
In practice, perhaps one can use hot water radiators in series. AIUI, most people want the bedrooms a little cooler than the rest of the house, for more comfortable sleeping. And if someone cooks a lot, that makes heat in the kitchen. Of course they also have these differences, and the sizes of the rooms, in mind when they put different size radiators in different rooms.
That means they could make the 2nd radiator in series bigger than the first, and the third bigger still. to make up for the water being less hot. I don't know if that is done.

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wrote:

I've thought about this and I'm sure it's not done. And that or keeping some rooms colder was the only way series radiators could work. I don't think either method is used and I'm 99% sure no one has series hot water radiators.

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micky;3105771 Wrote: >

The hot water radiators are plumbed in series in every apartment in every apartment building in every city in North America. They are plumbed in series so that when that apartment's thermostat calls for heat, it causes the zone valve in that apartment to open and hot water to flow through each radiator in the apartment; one after the other.
And, it's true that the temperature does diminish as the water flows through the radiator train, but it's not all that much. In my boiler room I have temperature sensors for both supply and return, and the difference between the water supply temperature and the return temperature will typically be between 10 and 20 degrees F.
--
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Wrong! if all rediator are plumb/hooked up in series why do we have zone valves?
They are

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grumpy;3107869 Wrote: >

>

In an apartment block, normally all of the radiators in each apartment as well as the zone valve are connected in SERIES. So, each apartment represents one radiator "loop".
However, all of the radiator loops are connected in parallel. That way, hot water will flow through all of the apartments whose zone valves are open, but won't flow through any apartment whose zone valve is closed.
It's the same thing with houses. You have different radiator loops in your house. All the radiators in each loop are connected in series, but the loops are connected in parallel.
If you have a two story house, then typically, all of the radiators on each floor are connected in series, but the two radiator loops are connected in parallel.
If you don't have zone valves on each loop, then you have to have "balancing valves" on all but the longest loop so that you can pinch off flow through the shorter loops to force more flow through the longest loop. Otherwise the lion's share of the hot water will always flow through the shortest straightest loop because it offers the least resistance to flow.
The downstream radiators in each radiator loop WILL be cooler than the upstream radiators because of heat loss along the length of the radiator loop.
Proper balancing valves will have ports on them where you can connect a pressure gauge to measure the pressure drop across the balancing valve. You open or close each balancing valve to get the same pressure drop, and hence the same flow, through each balancing valve. You don't have to bother with that if you have zone valves that are each controlled by a thermostat.
--
nestork


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