Advice for dialing in TT Prestige Solo


  #41  
Old 12-08-09, 09:02 PM
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Originally Posted by DanielNJ View Post
My contractor left everything set at the defaults and the house is a few degrees too cool right now, plus I'm sure the system isn't running anywhere near proper efficiency.
What exactly do you mean by too cool? Is the boiler not able to get the rooms up to the setpoint of the thermostat? Or is it just taking a while to get up to temp?
 
  #42  
Old 12-09-09, 01:45 AM
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Originally Posted by generaltso View Post
What exactly do you mean by too cool? Is the boiler not able to get the rooms up to the setpoint of the thermostat? Or is it just taking a while to get up to temp?
The main floor thermostat is set to 69 degrees but the boiler only satisfies that temperature some of the time, otherwise it's been hovering around 66. We're not setting the thermostat back, it's just dropping off on its own. I was told the factory default setting of 86 degrees needs to be raised in Parameter 10, "CH Minimum Boiler Operating Setpoint." But I'm sure there must be more to it than that, considering how all these parameter settings interact with each other to create the OD Reset curve, right?
 
  #43  
Old 12-09-09, 05:50 AM
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Yeah, there are more parameters that you can adjust to get your curve dialed in, but raising the minimum setpoint should help get enough heat in the space to maintain your thermostat setpoint for now. You could also increase the minimum outdoor temperature setting. The default is 0 degrees, but if your design temp is 12 degrees, it probably doesn't need to be set at 0.
 
  #44  
Old 12-09-09, 02:09 PM
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I spoke to the local distributor that we bought the boiler from, who seems pretty knowledgable about both the equipment and of course with the local area. He said I should set my low setpoint to 120 because with fin-tube baseboards, anything lower than that doesn't produce enough heat to really do anything. He said to set the high point to 170-175. For the design temp (coldest day) he said use 18 in this area. And for warmest day he said it's a matter of personal preference, anywhere from 55 to, say, 65, depending on when you want the heat to kick on during a warmer day. So I guess I'll use those as my starting points unless anyone here thinks that advice was severely flawed for some reason.
 
  #45  
Old 12-09-09, 02:17 PM
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That doesn't sound like bad advice to get the heat you're looking for. From my experience, I don't think you need the low setpoint that high. It will work, but it will use less fuel if you can get away with lower water temps. By setting the starting point at 120, you'll be spending less time condensing. My low point is set to 86 degrees.

Start with the distributor's recommended settings and see how it works for you. If you want to start tweaking it for efficiency, adjust some parameters and see what happens. I'm still tweaking mine, but I think I have it pretty close to where it will stay. I'll know more when the temp drops below zero.
 
  #46  
Old 12-09-09, 02:25 PM
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Thanks Generaltso. The TT factory default low point is 86, and it's too cold in our house with it set there. So I'll bump it to 120 and maybe try tweaking it down from there over time to see if I can find a sweet spot lower than that. Are you running slant-fin type baseboards in your house, or something else?
 
  #47  
Old 12-09-09, 03:59 PM
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Yup, I'm running slant/fin baseboard. Keep in mind that the low set point (86 in my case) will only get that low when the temperature outside is warm. With my settings, I've been getting a water temp of around 112 with temps outside around 30. That's been doing a good job keeping my house at 67 degrees and keeping the boiler in the condensing range.
 
  #48  
Old 12-09-09, 04:23 PM
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But if it's true that fin-tube is ineffective at water temps below 120, then I wonder how much someone may be wasting by running the system at temps from 86 ~118 on the warmer days. If the baseboard doesn't warm up enough to do anything at those temps, then it seems like you'd just be using up fuel to heat up the CH water for no reason on those days.

I guess the question is how useless fin-tube really is at water temps under 120. Both our local distributor and a tech support rep at TT headquarters itself recommended 120 degrees as the low set point for fin-tube baseboards.
 
  #49  
Old 12-09-09, 04:30 PM
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The water in my baseboards right now is 110 degrees. It's doing a wonderful job of keeping my house at 67. I think it's a bit of an exaggeration that water temps below 120 are useless. I've only seen water temps above 120 a couple of times since the boiler was installed. I think the useless temp is probably closer to 85. Even at 90 degrees, it doesn't emit a ton of heat but it doesn't need to since the heat loss of the house is pretty low when it's so warm outside.
 
  #50  
Old 12-09-09, 05:15 PM
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The heat that the boiler generates HAS to go somewhere.
So it will go into the rads and then into the air.
It just does not do it very well, but thats ok because we don't need that much heat.

You may find that the boiler modulates right down and has a hard time staying at set point and it will actually cycle because it's over its differential.

This is ok as well, as the water temp gets warmer the rads pull more btu out of the water, kinda self balances (to a point).

Too low of a water temp may be bad for the boiler in the form of cycling the burner.

I would rather see a bit higher water temp and some quicker response than lots of burner cycles.

What do you need to know about BOOST ???
 
  #51  
Old 12-09-09, 05:20 PM
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Originally Posted by TOHeating View Post
What do you need to know about BOOST ???
Boost seems counter productive to me. If the ultimate goal is constant circulation, wouldn't boost prevent that from happening?
 
  #52  
Old 12-09-09, 07:31 PM
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Fin-tube has useful output well below 120. How low you can go depends on how much fin-tube you've got, the rate of heat loss, how clean the fin-tube is, etc.

I got a house full of slantfin or equivalent baseboard, sized 30 years ago for 180F supply at 0F outside. Or if they didn't size it, they lucked out and got pretty close. Anyway, it will keep the house at 68F using 85-95F water for a range of temperatures from just when the house starts to need heat down into the low 40s. At those supply temperatures, the dT on supply/return is pretty small, so there's a long off-cycle. (And keep in mind I'm not running a TT boiler, but a fixed-fire hunk of cast iron with primary/secondary and a control with outdoor and indoor sensors. But the principle is the same.)

Point being that if 86 doesn't do it, no need to go leaping up to 120. Try 95 for a couple days.
 
  #53  
Old 12-09-09, 07:34 PM
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Well, the whole point of the excersise is comfort right ?
Otherwise we might just as well be burning wood in open fireplaces.

Boost will compensate and provide short recovery for set back periods, it will compensate for those few days when the outdoor temp is LOWER than the design temperature and ensure you don't loose heat that you might otherwise.

It can mess things up if not set responsibly, but can be a great feature to provide outstanding comfort and performance to the customers heating system.
 
  #54  
Old 12-09-09, 07:35 PM
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Originally Posted by generaltso View Post
Boost seems counter productive to me. If the ultimate goal is constant circulation, wouldn't boost prevent that from happening?
At times, it can. As I interpret it, boost is for those times when the straight ODR curve just isn't making it. Windy days with high infiltration, for instance.

ODR is a good leap forward, but IMHO a better leap forward is ODR with indoor sensing, which actually watches the temperature trends in the building and adjusts accordingly. Plenty of ways to do that, just not truly commonplace yet.
 
  #55  
Old 12-09-09, 08:38 PM
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Originally Posted by xiphias View Post
Point being that if 86 doesn't do it, no need to go leaping up to 120. Try 95 for a couple days.
Thanks, I'll give that a try. Does 170 sound like a good high setpoint? Guess I'll find out in a month or two, won't I?
 
  #56  
Old 12-10-09, 10:00 AM
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Originally Posted by TOHeating View Post
What do you need to know about BOOST ???
OK I understand the benefit of boost. You want it to be available for those times when you need higher recovery temperatures for any number of reasons.

So let's say I get my ODR curve set up to maintain 70 degrees in the house under normal circumstances. To do this, I temporarily set my thermostats really high (say, 80) but then adjust the boiler parameters so the water flows through the system continuously and keeps the air temperature right at 70. Now when I set my thermostat back to 70 where I want it, in theory it should stay open most of the time so the water keeps flowing continuously through the radiators to maintain that temperature. That way the system is running at maximum efficiency. Is that right so far?

But now if I program the Boost setting to kick in after the thermostat has been calling for heat for more than 15 minutes, that means the boiler will probably ramp up at least a couple times per hour to get over that threshold, instead of running continously to maintain the desired temperature, won't it? That would seem to defeat the goal of keeping the water flowing constantly at just the right temperature for maximum efficiency.

So what is the correct way to configure this? Set up the initial boiler parameters a couple degrees warmer so the system naturally maintains, say, 72-73, and the thermostat cycles on and off when set to 70? Or set the Boost time to something more than 15 minutes? Or something else?
 
  #57  
Old 12-10-09, 10:30 AM
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Originally Posted by DanielNJ View Post
But now if I program the Boost setting to kick in after the thermostat has been calling for heat for more than 15 minutes, that means the boiler will probably ramp up at least a couple times per hour to get over that threshold, instead of running continously to maintain the desired temperature, won't it? That would seem to defeat the goal of keeping the water flowing constantly at just the right temperature for maximum efficiency.
Exactly. I think the boost feature is really just for people who can't get their head around the way that a mod/con works. It makes it behave a little more like a conventional boiler in that it will keep using hotter water until the thermostat is satisfied. If you understand the way outdoor reset works, and you're willing to get rid of thermostat setbacks, you really don't need boost.
 
  #58  
Old 12-10-09, 01:13 PM
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Originally Posted by TOHeating View Post
Too low of a water temp may be bad for the boiler in the form of cycling the burner.
Why is it bad for the boiler to cycle the burner often? My burner does a lot of cycling, but if I change my ODR curve to increase the water temp I'll get boiler short cycling, no?
 
  #59  
Old 12-10-09, 02:59 PM
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Burner cycling = boiler short cycling

Pretty much anyways.

If the water temps are a bit higher than they need be the stat should get satisified earlier, but room swings will get higher.
 
  #60  
Old 12-10-09, 03:02 PM
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Originally Posted by TOHeating View Post
Burner cycling = boiler short cycling

Pretty much anyways.

If the water temps are a bit higher than they need be the stat should get satisified earlier, but room swings will get higher.
But isn't peak efficiency achieved when the thermostat never gets satisfied and there aren't any room swings? I thought the goal was to only put enough heat into the space to match the heat loss so that there's continuous circulation.
 
  #61  
Old 12-15-09, 05:44 PM
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Originally Posted by generaltso View Post
But isn't peak efficiency achieved when the thermostat never gets satisfied and there aren't any room swings? I thought the goal was to only put enough heat into the space to match the heat loss so that there's continuous circulation.
yep thats the goal.
But it's impossible to hit in reality.
I would rather store some extra energy in the house with a little larger temp differential than I would have a boiler cycle every 2 minutes.

In the old days we would store a bit of extra energy in the cast iron of the boiler with a nice big aquastat differential. In mod cons we can't do that too much so they start to cycle.

Peak efficiency so be regarded as the overall system efficiency, take into account starting a boielr at mid fire for a minute or so until the flame stabilizes then it can modulate down. By that time the water temp is getting past the high side of the differential and the load is to small to drag it back down.
Life would be great with a very high turn down modulating boiler.
 
  #62  
Old 12-15-09, 05:50 PM
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Originally Posted by TOHeating View Post
yep thats the goal.
But it's impossible to hit in reality.
I think I'm pretty darn close with my upstairs zone. My thermostat is set at 67* and the space temp seems to ALWAYS be 66.5* with constant circulation. But the burner rarely runs for more than a few minutes at a time. Are you saying that I would be better off using hotter water and having room temp swings so that the burner runs for longer periods of time?
 
  #63  
Old 12-15-09, 05:56 PM
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Originally Posted by generaltso View Post
I think I'm pretty darn close with my upstairs zone. My thermostat is set at 67* and the space temp seems to ALWAYS be 66.5* with constant circulation. But the burner rarely runs for more than a few minutes at a time. Are you saying that I would be better off using hotter water and having room temp swings?
No, if you have the load to match the minimum modulation of the boiler than you have done what you can.
Sit down, grab a beer, or glass of wine, or whatever and relax and enjoy your accomplishments.

If you boiler has good long run times then you win, 5 minutes / 10 minutes cycles are great. If the flow is right you will be off for a good deal as well.

Quite a number of systems are zoned, and zoned systems and mod cons and outdoor reset have many variables to them. Trying to hit the moving head of a nail is hard. PID logic is good, but doubling the flow and increasing the load 2 fold will play havoc on many a system.
 
  #64  
Old 12-15-09, 06:02 PM
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We'll see if the curve stays linear as the temp outside drops or if I need to do more tweaking. The zone on the main floor usually gets satisfied fairly quickly. I'm guessing that's because the heat loss upstairs is higher.
 
  #65  
Old 12-16-09, 05:31 AM
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if you have installed globe valves at the zones you can try to throttle the flow somewhat in order to length the one time.

This will raise the delta T of course and may or may not be an issue.
 
  #66  
Old 12-17-09, 06:56 AM
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The temp outside dropped to about 2F today. My curve still looks pretty good. I've still got constant circulation in the upstairs zone and the water temp is up to around 135. The burner is staying on for a good 10 minutes at a time with these temps. It's nice to see that I'm still condensing with outside temps near 0F.
 
  #67  
Old 12-18-09, 12:08 AM
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Well there must be something wrong with mine then. With the outside temperature at about 20F, It's cranking out 180 degree water yet barely maintaining the temperature on the main floor. If I enable Boost it will kick up to 200 degrees just to keep up. Meanwhile the other zones in the house are able to gain several degrees per hour if I raise their thermostats above 70, it's just the main floor that's creating all that demand.

If this boiler should be idling along at ~135 on a 2 degree day, I guess I must need to add some baseboards on the main floor.
 
  #68  
Old 12-18-09, 04:37 AM
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Originally Posted by DanielNJ View Post
Well there must be something wrong with mine then. With the outside temperature at about 20F, It's cranking out 180 degree water yet barely maintaining the temperature on the main floor. If I enable Boost it will kick up to 200 degrees just to keep up. Meanwhile the other zones in the house are able to gain several degrees per hour if I raise their thermostats above 70, it's just the main floor that's creating all that demand.

If this boiler should be idling along at ~135 on a 2 degree day, I guess I must need to add some baseboards on the main floor.
The water temperature is decided by the reset curve. The reset curve is determined according to the heat loss. Every house is different.

What's your design outdoor temperature?
What's the heat loss at design?
How much radiation do you have?
How many BTU/hr will the radiation output using 180F water?
Is the boiler cycling or is it running constantly when it's doing the 180F water at 20F outside?

Answering those can get you started toward evaluating what the boiler should be doing at a particular load (outdoor temperature), and what might make the most sense in terms of tuning the curve, adding radiation, and reducing the heat loss. Reducing the heat loss by insulating and air sealing is almost always the best first step and has the shortest payback.
 
  #69  
Old 12-18-09, 05:36 AM
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You also might want to start a new thread if you think you have some problems that need resolving.
 
  #70  
Old 01-16-10, 05:42 AM
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new tt solo 110 owner

Great project. I have questions so far. can someone please tell me when venting the combustion air do you pitch it to the boiler to get to the condensate pump or out of the house? Does anyone what to help with dialing this thing in, or do I go by the book?
 
  #71  
Old 01-17-10, 09:41 PM
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Originally Posted by RYSDAD814 View Post
Great project. I have questions so far. can someone please tell me when venting the combustion air do you pitch it to the boiler to get to the condensate pump or out of the house? Does anyone what to help with dialing this thing in, or do I go by the book?
Not great to jump into this thread, you should start a new one really.
But...

Pitch the vent towards the boiler, if you install the vent according to the vent supplement and you slope towards the outside you will have large problems.

If you need help dialling it in, just ask. Many here to help
 
  #72  
Old 02-06-10, 04:03 PM
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can someone help me tweak my solo 110

I have my odr set at 22F and my minimum boiler temp at 110 and max at 168. I have a 2200 sf home with 2 zone baseboard heat. I have 2 taco 007 pumps for the zones, 1 taco 007 pump for the indirect and the pump with the system for the primary loop. my boiler seems to call for heat every half hour and run for around 10 to 15 minutes. The supply and return temps differ by 10 to 15 degrees until the system is satified they they are about equal. is this normal? some one please help and pm me with your email and I'll send pics of the system.
 
  #73  
Old 02-06-10, 04:13 PM
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Originally Posted by RYSDAD814 View Post
I have my odr set at 22F and my minimum boiler temp at 110 and max at 168. I have a 2200 sf home with 2 zone baseboard heat. I have 2 taco 007 pumps for the zones, 1 taco 007 pump for the indirect and the pump with the system for the primary loop. my boiler seems to call for heat every half hour and run for around 10 to 15 minutes. The supply and return temps differ by 10 to 15 degrees until the system is satified they they are about equal. is this normal? some one please help and pm me with your email and I'll send pics of the system.
I'm not sure what the design temp should be for NJ, but 22F seems a little high to me. If your boiler is short cycling, I think you can safely reduce your curve. You could start by lowering both the minimum and maximum water temps and see what happens.
 
  #74  
Old 02-06-10, 04:47 PM
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ijust did a 90 min 150 max and the coldest day at 16
 
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Old 02-06-10, 04:50 PM
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Originally Posted by RYSDAD814 View Post
ijust did a 90 min 150 max and the coldest day at 16
See how that does. If it still seems to satisfy quickly, you can lower the curve some more.
 
  #76  
Old 02-06-10, 04:51 PM
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what does lowering the temps do? I thought the min for baseboard hot water was 120F
 
  #77  
Old 02-06-10, 04:57 PM
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Lowering the water temp saves energy. You want to use the coolest water possible to maintain your space temp. Depending on the outside temp, baseboard can be effective at temps well below 120F. My minimum water temp is still at the default setting of 86F, and my design temp is around -10F.

By the way, it looks like the design temp for NJ is between 0F and 5F, depending on what part of NJ you're in.
 
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Old 02-06-10, 05:27 PM
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great thanks for the info.
 
  #79  
Old 02-06-10, 06:54 PM
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According to the ASHRAE manuals the OD reset for New Jersey is between 6 and 14 degrees depending where you are.
Here is a link to their charts.
Technical Menu Click or Outdoor design temperatures.
Also a link to help explain OD reset
Same link as above click on what is OD rest on the menu.
 
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Old 02-07-10, 04:29 AM
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I had to raise the min temp to 100 and max to 150. The 1st floor was 3 degrees cooler than the set temp with it 22 degrees outside
 
 

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