Two thermostats

[Deleted User]

In follow up to Bills response, We have a 2 zone/upstairs/downstairs set up. The thermostat is located in the up stairs hallway, I feel the upstairs zone is effected greatly the downstair rising heat. Is the upstair hallway the best location for the thermostat? Or should it be in the Master bedroom with TRV,s on the other rooms? What location will give us the best control of comfort?

F Reynolds

Two thermostats

(Don’t be too rough on the idiot here, just a thought for discussion.)

Ok, we know that hot air rises. A neighbor tells me you can loose at least 15% if not more of the downstairs warm air when it moves up the stairwell. I have decided against two zones, however, would a second thermostat located upstairs also serve to help efficiency?

Here is the thought process: When I go to sleep at night, I’m really only concerned about the temperature of the upstairs (bedroom) area. Why should the thermostat in the living room downstairs be the one that I use to maintain upstairs bedroom temperate. Also, generally speaking, what is the temperature difference between a lower and upper floor with a one zone hot water heating system?

If I had a separate thermostat that takes over as primary at night upstairs, (with the downstairs one at a night setback of about 64 degrees so it would not activate the heater) the heater would only go on to satisfy the upstairs thermostat, using the 15% that goes up the stairwell, and not be concerned about what is happening downstairs. JUST TRYING TO THINK OUTSIDE THE BOX HERE.

Can you tell, I don’t know a lot about this stuff. Please kick it around; I’d like to hear your comments.

F Reynolds

joe_14

it depends



to do what you are saying you need to zone the upstairs and downdstairs seperatly. this is the only way you can control the heat between upstairs and downstairs. if its not zoned you are fighting a losing battle.

joe.g

F Reynolds

I understand, but

Thanks Joe, I understand but when I go up for the night, the only tempature I care about it is the temp upstairs. My point is, why care about the tempature in the livingroom. I totally understand your idea about the two zones and agree on it in principal. However, isn't it more important that the upstairs is 68 degrees at night, than it is is 68 degrees in the livingroom?

Mark Eatherton1

The boiler doesn't know

which floor is calling for heat if it is a one zone system with two floors. Maybe you should consider a continuous circulation system with non electric thermostats with programmable capabilities. Finding someone to do it might be easier than you think. Check Find A Contractor.



ME

Bill NTSG

Why Would

any one want to set back at night? Why do pipes freeze?

Because it is usually colder at night, and the once 70° house has to cool down to 60°. The heat pipes in the overhangs and crawl spaces have no circulation for a long time and freezzola.

I can see setting back in the day time when you get solar gain and no one is home. Viessmann , Tekmar and others can allow you to set back the water temp but keep the constant circ.

What I really love for an answer is "It was supposed to get really cold, so I turned the heat down" It might cost $4-5 for the fuel , but it cost hundreds or thousands to repair the water damage when the pipes freeze and burst.

Mr. Reynolds, you may never be comfortable until you zone that system. I lived that upstairs downstairs nightmare for two years when I first got married. It cost me probably $200 to zone the two floors. I got my money back in fuel savings and was much more comfortable. A Very small price to pay for a decent nights sleep!

Firedragon_2

I'm a great believer in setback

thermostats, got 5 in my own home, two setbacks per 24 hrs. and yes the Feds/Doe are right you can save 11% annually, FACT!

What you're talking about however is the old Master/Slave system. It was replaced by the clock thermostat and as many have told you won't really do anything except what one good clock thermostat will do and zoning will do better.

GaryDidier

Thermoststs

Either blow for the two zones so you have better controll or use a setback thermostat on the one zone and invest in a down quilt or an electrick blanket. Hows that for outside the box!
Gary from Granville

BillW@honeywell

It's not clear what kind of system you have...

but both hydronic systems and forced air can be zoned. The concept is simple, you don't have one light switch to control your lighting, do you? A thermostat controls a zone valve or zoning panel for hydronic, or a zone damper for forced air. Bill's idea of constant circ is a good one if you have hydronic heat, also, you can get a reset system for your hydronic heat that varies the water temp with the outside temp, automatically, and may eliminate your need for either setback or zoning, depending on how your house is set up. There is no equivalent for forced air; if that's what you have, consider a zoning system. Check out customer.honeywll.com/enviracom. Good luck!

F Reynolds

Speaking of a reset system

Speaking of reset system for your hydronic heat that varies the water temp with the outside temp, automatically, I'm having a Weil-McLain Ultra 155 installed next week. I'm serious about improving efficiency. Actually, I currently have a gravity fed, single zone system, with separate supply and return lines, a Hydrotherm Boiler (circa 1977), 180K BTUs in, that heats Weil-McLain low baseboards. I have a Honeywell Programmable Therm that has worked very well. Other than insulation (and I have a great deal of horror stories) placed in my house before I purchased it, I was thinking about upstairs bedroom heat. I do have an estimate for repiping and creating a second zone for my bedrooms ($2700). Decided not to do it. I also considered an Indirect Fired Water Heater, but old one is a direct fired and only three years old.

Oh, by the way HEAT DOCTOR, you are not supposed to make fun of the idiot. Yes, I do have an electric blanket, and a wife thank you! We will skip the "in the box" thing. So, I was wondering what a second thermostat in my bedroom area would do. Should I make the heater work to satisfy the thermostat in the bedroom at night and the family room during the day? I'M ONLY INTERESTED IN THE TEMP OF THE HEAT IN THE BEDROOMS AND NOT IN THE LIVINGROOM AT NIGHT! I was just wondering, kind of kicking it around, putting it out for discussion, interested in your opinion about the difference in heat temps upstairs vs. downstairs, when the thermostat is in the living room. Come one guys, I'm thinking on a simple level here, I really don't know what the heck I'm talking about and trying to get a little of your knowledge. Maybe I should also just get a down comforter and a second wife, huh Heatman? Thanks for your advice. Interesting exchange of ideas. (Ok, Insulation, want to talk insulation now. How about “my attic insulation’s moisture barrier (facing)” is facing towards my unheated attic, and my “do not leave this facing exposed because it is very flammable insulation”, exposed facing in the crawlspace under the family room. EXPOSED!) Heatman, were you once InsulationMan and did you install the insulation in my house? F Reynolds

Rob T

Actually we

set back at night for comfort. I absolutely hate waking up in a warm bedroom so the master bedroom in my house is a zone by itself and is set back 4f at night.

As far as pipes freezing, all of mine are in a heated basement or in the living space area of the house so that is not an issue.

Just a random thought.

Rob

Rob T

I don't see

any problem with using 2 thermostats myself as long as they are programmed correctly.

You want to have control of your system from the main floor during the day when you are using that area and the upper floor at night when it is being utilized right?

Sounds fine to me, of course I am just a home owner with 25+ yrs experience in construction...

Good Luck

Rob

F Reynolds

THANKS ROB

Rob, you can have my second wife (if I need another to keep me warm in the winter) during the summer. That's what I needed, some positive encouragement. Thanks, yes, you got it!

Mike T., Swampeast MO

Just installing a second thermostat on a single-zone system really won't produce the effect you desire. In a system of truly perfect balance it would have ZERO effect.

Yes, a lot of warm air flows up into stairwells. BUT such is generally considered when designing the system in the first place. Typically heat sources sufficient to heat the ENTIRE stairwell space is installed at the lower floor with little or no heat source in the upper.

This situation might result in a bit warmer temperatures upstairs than downstairs--particularly in the stairwell itself. Something similar (literally holes in the floor) was used in old gravity "pipeless furnace" systems.

Your system however has individual heat sources in the upstairs AND downstairs spaces. The level of temperature balance depends on how the system was initially designed. You can change such a bit by opening or closing upstairs doors or running fan(s), but please forget about that right now...

Merely changing the location of the (or adding an additional) thermostat will have ZERO effect on this temperature balance. If your upstairs already tends to overheat relative to the downstairs, it will STILL overheat by this same amount regardless of the placement or number of thermostats.

Similarly, if the upstairs and downstairs are already reasonably balanced temperature-wise, changing the location or number of thermostats CANNOT IN ANY WAY result in a condition whereby the upstairs magically stays warmer than the downstairs.

I wish I could tell you that there is some way to use that heat flowing up the stairwell in any way OTHER than the position of doors and/or fans, but there is no way in the system you describe.

Please look into thermostatic radiator valves (TRVs). These allow you to keep each and every room at its own temperature independent of the rest and without any major piping changes. TRVd systems often do require minor changes in piping around the boiler, but you are getting a new boiler soon and now would be the least expensive time to install them.

TRVs offer energy savings in MANY different ways--some in your control, others beyond your control.

F Reynolds

Thanks Mike

That was exactly the answer I was looking for. Thanks.

Steamhead

FR, here's what a (Honeywell/Braukmann) TRV looks like

when installed on a radiator- one of my own radiators. This is an old converted gravity system like yours, and all the radiators are 2-pipe. You turn the dial to whatever temperature you want and the TRV stops the water flow when the room reaches the setting. They really do work well.

If any of your W-M baseboard is piped in series or with Monoflo tees, you will need a bypass around each TRV-equipped baseboard to maintain the proper flow thru the system.

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F Reynolds

Ok, OK, Two zones

I have been all over this house. From consulting my Reader's Digest New Complete Do-It-Yourself Manual, I have determined I have a two-pipe hot water heating system. With a dedicated line for hot water and a dedicated one for return of cooler water. It would seem to me, that to create a two zone system, I (sorry about that, after the discussion I have created here, do you think I would do it) believe one would only have to run a parallel supply pipe and connect it to the upstairs feed lines, and the existing supply line would continue to handle the downstairs. Of course I would have to cap off the areas on the existing supply line where the connections to the upstairs used to be.

#1 Assuming this is true, I would not have to run a parallel return line would I?
All the return lines are already connected to the return side of the convectors, and I wouldn't have to touch them at all. I could just keep the return lines as they are.

Additionally, I wouldn't have to, if I didn't want to, have two circulator pumps; I could do it with only one. (I know in a perfect world there would be two circulator pumps, but I would only need one).

So, I would need two zone thermostats for the pipes, two thermostats (one for each zone), and new parallel supply piping? Is this correct? F. Reynolds

Mark J Strawcutter

number of zones

If you're going to go to all the trouble of running new supply piping to the upstairs risers and installing zone valves, why not give each room it's own zone?

Put TRVs on the radiators, a differential pressure bypass to protect the circulator, and switch to constant circulation?

Mark

Cliff Brady

I am considering TRVs for my single pipe

gravity take off system. My system is the kind with a 60 foot rectangular loop of 3 inch cast iron in the basement in which supplies to radiators come off the top of the main and returns back into the side of the main. Seems like a great setup for constant circulation and outdoor reset. Additionally, a little more heat could go to the basement as the radiator pipes are currently the only real heat source there.

My questions: is there much risk of damage to the old circa 1906 radiators when removing the old 1 1/4 nipples with a radiator wrench? Even with professionals in to do the job is there much chance a radiator would be broken and the system couldn't be refilled that same day? Are thread loosening products like liquid wrench sometimes used are they possible contaminants to the system?

Mike T., Swampeast MO

I've yet to break an iron radiator when removing the tapping bushings--even with a 48" wrench and breaking bar. They can be stubborn as hell but they come out eventually.

I haven't though ever been able to remove the old union tail pieces from the bushings, so plan on installing new black iron bushings.

When installing TRVs do not trust that the valve is installed on the supply side of the radiators! Trace the lines to EACH AND EVERY radiator!

Watch out with TRVs on one-pipe systems. ALL introduce much more restriction than the old giant valves and you may or may not get flow through the radiators. Find TRVs with the lowest possible cv rating. Check with the mfgr regarding your installation and system. To quote Dan Holohan, "...if they say not to worry about it, worry about it, hang up and go somewhere else."

Cliff Brady

> I haven't though

> ever been able to remove the old union tail

> pieces from the bushings, so plan on installing

> new black iron bushings.


Do you mean that the tailpiece generally doesn't come out of the bushing even when using a radiator wrench inside the tailpiece, ie the bushing turns instead of the tailpiece?

>

> When installing TRVs

> do not trust that the valve is installed on the

> supply side of the radiators! Trace the lines to

> EACH AND EVERY radiator!

>


I have seen that advice here numerous times and my radiators fortunately have all the valves on the supply side.

> Watch out with TRVs

> on one-pipe systems.

Is this still the case where all flow up to and down from the radiators is done individually by gravity off the 3 inch single pipe main which acts as kind of resorvoir of hot water? Flow rates to each radiator are rather slow at the rate of gravity.

ALL introduce much more

> restriction than the old giant valves and you may

> or may not get flow through the radiators. Find

> TRVs with the lowest possible cv rating. Check

> with the mfgr regarding your installation and

> system. To quote Dan Holohan, "...if they say

> not to worry about it, worry about it, hang up

> and go somewhere else."




I am thinking of specifying the giant and pricey HONEYWELL-BRAUKMANN V110E1028 1 1/4 inch angle model. The horizonal angle model has a cv of 8. These would team up with the T104F1512 remote temperature sensing and integral set point actuator.

Mark J Strawcutter

pasco radiator spud key

I've had good luck removing the tailpieces while leaving the bushings intact by using Pasco radiator spud keys (not their spud wrench). The spud keys are machined and case hardened, the wrench is pretty crappy cast metal.

see http://www.pascospecialty.com/images/Pasco.pdf then go to page 121. Item # 4486 is 1in (size is missing from catalog).

I did have some trouble using them with Danfoss TRVs. While the threads were NPT, I suspect they used the closest metric size tailpiece casting. I had to get a second spud key of each size and grind them down a bit to fit in the danfoss tailpiece.

Mark

Mike T., Swampeast MO

Do you mean that the tailpiece generally doesn't come out of the bushing even when using a radiator wrench inside the tailpiece, ie the bushing turns instead of the tailpiece?

In the 40 or 50 rads I've done, I've yet to remove a tailpiece. The lands that are engaged by the spud wrench either tear off or the nipple AND bushing come out together. (It doesn't do much for the expensive spud wrenches either.)

Perhaps it has something to do with the age or the local water--not sure. Some say they can remove the tailpieces, but even trying such with two big wrenches (knowing I'll destroy the tailpiece) I just wind up with skinned knuckles and a bruised ego.

No reason you shouldn't try it, but you can always replace it bushing and all. New ones aren't as compact as some of the old ones, but I haven't had a problem yet.

Mark J Strawcutter

geometry

I also discovered (too late) that Danfoss makes valve union tails in various lengths.

I had a situation where the dead men came out of the rad with a close nipple, into one of those straight couplings like are often included with a joint of pipe, then the valve union tail. Really had to lean on the wrenches to get everything "short" enough.

I hasn't leaked, and is hidden back in a corner, but it would have been cleaner to get a longer valve union tail.

Mark

Steamhead

Cliff, that's an old \"one-pipe gravity\" system

If you're going with TRVs, get the ones with the least resistance to flow (higher Cv number) that you can find. You don't have a whole lot of force to move the water up into the radiators to begin with, so a TRV with lots of resistance can cause big problems.

And you should also be using a very small circulator, to mimic the gentle gravity flow in the main.

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Mike T., Swampeast MO

Thanks for the correction Steamhead

I said "lower" cv. I knew and meant "higher", meaning more flow, less restriction but it's one of those stupid mistakes that I find too easy to make...

Kind of like "lower delta t means more output", but only when everything else is constant. (At least I think that's right.) Or is it only if flow has increased in as the delta t has decreased? Hideously confusing to me.

Mark J Strawcutter

kinda like...

"turn down the A/C"

Mark

F Reynolds

Are TRVs really the way to go

I may not have been clear about my system. I have a snug baseboard system like these

http://www.weil-mclain.com/radiant/snug.htm

I don't think I could easily put TRVs on them. Secondly, why would it not be a good idea to run a second zone upstairs. I would only have to connect a seperate (main) supply pipe to each of the four pipes running to the second floor for each of the four baseboards. The second supply line would run along the outside of the basement, and connect to each of the four that go upstairs. Seems easy to me. What do you think?

F Reynolds

For Mr Strawcutter (TRVs?)

Did you catch my last posting about my snug baseboard radiators? Unfortunately, with all the discussion about TRVs, it would seem to be the way to go, but I can't use them. Ugh, life would be a lot easier...

Cliff Brady

Cv of 8 for the Honeywell-Braukman

seems pretty high but I haven't compared it to other 1 1/4 inch TRVs.

I hope you consider 14 GPM gentle. I know its not but the takeoffs seem to output just fine pushing the 26 gallons of water in the main around in just over two minutes. Roughly 1/2 feet per second doesn't sound to bad for a 3 in main

I think it was a Dan H. article about circulator sizing on gravity systems that seemd to conclude that higher flow rates were better but I think it was mostly dealing with 2 pipe systems. I know the risk of higher flow would be less stratification to promote the gravity flow.

Thanks to all for wighing on this subthread it certainly deserves a thread of its own.

Josh Schneider

Removing tailpieces

Hello. I just did a rehab job on an old gravity system, piping in new mains and putting Honeywell TRVs on all rads. I succeeded getting the tailpieces alone out without budging the bushings by taking my torch to the joint between the two for quite a while and using an 18" pipe wrench to loosen. I think I must've been far off in my approach, but I installed the new tailpieces with pipe wrenches and slim channel-locks (not spud wrenches or keys, which I now realize I should have used). Not the prettiest job on the outside, but with a good amount of wire brush cleaning of the old threads and a nice application of Gasoila, I've had no leaking whatsoever. The new Honeywell tailpieces fit in fine with the old bushings on my big old American Radiator Company units.