Boiler Short Cycling

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  #41  
Old 12-22-13, 06:41 PM
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get a plumber here asap and have him rewire
Perhaps that's the problem all along.

You need an ELECTRICIAN! Plumbers don't (or perhaps SHOULDN'T) do wiring!

Looking at pics now.
 
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  #42  
Old 12-22-13, 06:45 PM
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Hi. IMO since your boiler is a non condensating boiler I would ditch the ODR tekmar.. I feel there is no reason to have that with a boiler that should not go below 140F anyway....

My opinion, but others may agree is to remove it and rewire for the aquasmart heat manager.


The aquasmart works off thermal imaging and would be better suited for you needs... The short cycling can be improved by setting the diff wider... The aquasmart will lower the boiler temp also...

I read there are three setting but I am trying to figure how the set the boiler min for the heat manager...

Well thats my advice...

Sell the tekmar on one of the auction sites to recoup your money lost...


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  #43  
Old 12-22-13, 06:55 PM
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Hi lawrosa,

I can tell you that same thought has crossed my mind a few times...getting rid of the Tekmar and just using the AquaSmart....
 
  #44  
Old 12-22-13, 07:02 PM
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And its frustrating too because we thought we hired a Master Plumber that was competent with all this stuff...had good recommendations...etc....and a wiring mess is what I have to show for it.

NJ Trooper, what are your thoughts on ditching the Tekmar like lawrosa suggests?
 
  #45  
Old 12-22-13, 07:04 PM
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It was probably wired similar to this , although the indirect gets wired to the last zone in the taco panel if you want to use priority.......


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  #46  
Old 12-22-13, 07:05 PM
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Bottom line though is probably this:

Your short cycling problem is due MOSTLY to the oversize boiler and the small zones.

Ditching the 260 isn't going to solve that.

Yes, the wiring is a mess... very amateurish. Many 'code issues' that I can see. But not related to the short cycling.

Your 'pain' and what brought you here is the short cycling.

The other things aren't really related to that.

Yes, you should have a competent technician clean up the wiring and address the different issues with that, but it's not what's causing your 'pain'.

I've gotta git for the night... back tomorrow, same bat time, same bat channel.
 
  #47  
Old 12-22-13, 07:12 PM
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It was probably wired like this
Where'd that come from Mike?

I don't see the purpose of that 4 pole contactor in the circulator circuits.

I think the wiring is basically 'correct', but poorly executed. I'm not sure why they decided to run all the circ wires into that box up top (which is too small by the way... they couldn't even get the cover to fit flush there are so many wires in it). Did they think it would be neater? If so, then why didn't they keep up the 'neatness counts' attitude throughout the job?

NJ Trooper, what are your thoughts on ditching the Tekmar like lawrosa suggests?
Honestly, I probably would keep it.

I think Mike is confusing the AquaSmart with the HydroStat when he talks of 'thermal targeting'... the HydroStat is a different technology than the AquaSmart. I'm not keen on the AquaSmart "Heat Manager" stuff.
 
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Old 12-22-13, 07:36 PM
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I don't see the purpose of that 4 pole contactor in the circulator circuits.
Yeah that is puzzleing....

http://www.beckettcorp.com/protect/m...renceGuide.pdf

Its simiar to the hydrostat but changes temp on time based of how often the boiler fires... The hydrostat bases it on time of the t stat calling for heat...( I believe..)

The Beckett AquaSmart HeatManager calculation adjusts the high limit of the boiler based how long the system is on or off. If the system is calling for heat, the adjusted high limit will increase over time but never above the high limit set point. If the system is not calling for heat, the adjusted high limit will decrease over time. The minimum temperature the AquaSmart will allow
the adjusted high limit to drop is based on a number of factors including the high limit, low limit, differentials, and HeatManager efficiency settings



Yes possibly the tekmar is better..Hmmm... IDK....

How big is that boiler vs the heat loss?

Home ....1400 sq ft = 35000 btu's

Buderus G115WS/4 = 95000 btu... Uggggg!!!
 
  #49  
Old 12-22-13, 07:43 PM
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Troop not to get side tracked.....Buderus G115WS/4 has a .90 nozzle... I wonder if a .70 would help????
 
  #50  
Old 12-23-13, 07:18 AM
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Yeah that is puzzleing....
3. Circulator-on delay will affect all zones. Circulator-off delay will have no effect. If Circulator-on delay is not desired, remove the n-pole contactor and wire the circulators directly to the zone panel
It's a 'work-around' to allow the use of the circulator on delay in the aquasmart...

I wonder if a .70 would help????
I guess that would depend on whether or not Buderus allows 'down-firing' the boiler...
 
  #51  
Old 12-23-13, 10:46 AM
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Nozzle

Hi Again Guys...

First off, thank you for all your input yesterday...it is very much appreciated.

So I take it the boiler is waaaay oversized for the home. The last time I had it serviced the nozzle was changed and it said "Nozzle .75" on the sheet (the burner is Riello, but you probably already knew that). We also had a stainless steel chimney liner put in recently.

I want to tell you about something I saw on the Tekmar last night when it was cycling. I heard the thermostat click on for a heat call in an upstairs zone so I ran downstairs...boiler came on for awhile...then the circs for awhile...then boiler fired back up again for just a few seconds and shut down (on the Taco panel the zone light in the back went off so I assumed the heat call was satisfied). Right before the zone light kicked off, when I looked at the Tekmar panel the "Boiler Target Temp" was 150...and when I looked at the actual Boiler Temp on the Tekmar it was switching back and forth between 149 and 150...kind of like it was hung up....that's when the boiler fired for a brief few seconds and then shut down. It doesn't do this every time on a heat call...just every now & then...but I assume it shouldn't do that. It was like as soon as it fired up it immediately shut itself down. Could that just be a fluke and the heat call just happened to be satisfied at that precise time??? Or do you think its weird the boiler temp would be switching back and forth between 149 and 150? I think upping the BOILER MIN like NJ Trooper suggested is making it cycle better overall.

To sum up then, you guys think I definitely need the system wiring rechecked and redone. Could you elaborate a little more on connecting the two small upstairs zones together to make it one zone (without costly repiping)? Is that something I should consider having done? If there are any other suggestions of things I can do to help with the oversizing, please let me know. I don't mind putting money into this system to get it where it needs to be but my husband is in the military so this is definitely not our forever home.....

Thanks!
 
  #52  
Old 12-23-13, 10:57 AM
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Hi Vic, I can only give short answers ... (I'm 'sneaking' on here... at my 'day job')

The bouncing between 149 and 150 is probably not significant... but it's good to look for that type of thing happening... what you are seeing is just the fact that the temperature is right on the borderline between the two temps and the microprocessor is having a hard time deciding what to display... if you could take it out a decimal place or two, it might read 149.95 ...

More this evening...
 
  #53  
Old 12-24-13, 11:21 AM
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Hi NJ Trooper...

Another question (when you have the time, of course)...

I noticed that the boiler temp on the Tekmar display and boiler temp gauge itself are pretty close to each other...but when I checked the temp on the AquaSmart display it showed ten degrees higher than the Tekmar/boiler gauge. Is this to be expected?

Knowing how oversized this boiler is, would you still keep the boiler design temp at 180 with the boiler MAX at 190? Or would you change those? Since the AquaSmart is currently programmed with a High Limit of 190 can I be sure it won't conflict with the Tekmar or would you recommend setting the High Limit even higher on the AquaSmart (like maybe 210? or higher??) just to ensure there is no conflict between the AquaSmart and Tekmar? And can the current differential of 20 that is programmed on the AquaSmart stay that way or do I need to change that, as well?

As always, thanks for your help and Merry Christmas/Happy Holidays!
 
  #54  
Old 12-24-13, 12:52 PM
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So I take it the boiler is waaaay oversized for the home. The last time I had it serviced the nozzle was changed and it said "Nozzle .75" on the sheet (the burner is Riello, but you probably already knew that). We also had a stainless steel chimney liner put in recently.
Yes, oversized... at least based on what we know of your home.. but I'm sure it is.

OK, apparently the service guy has 'down-fired' your boiler already. As long as it's burning cleanly, they that's OK I guess, and a step in the right direction. Chimney liner = GOOD.

I noticed that the boiler temp on the Tekmar display and boiler temp gauge itself are pretty close to each other...but when I checked the temp on the AquaSmart display it showed ten degrees higher than the Tekmar/boiler gauge. Is this to be expected?
A few thoughts on this...

First, the water temperature is not the same everywhere inside the boiler. There could well be places where the water is hotter than others. This is due to the flow patterns of the water inside... whether the water is being 'stirred and mixed' evenly. It usually is not.

If you are seeing these differences AFTER a heat call has ended, and the pumps have stopped running for some period of time, what you are seeing is basically meaningless because there is NO stirring going on when the pumps aren't running. The heat that is in the cast iron after the burner stops firing continues to transfer to the water so there could be localized areas inside that are different temps.

Knowing how oversized this boiler is, would you still keep the boiler design temp at 180 with the boiler MAX at 190? Or would you change those?
Yes I would. Your heat emitters in the home need to be able to move enough heat into the home to keep it heated. There may be cold periods during the course of the winter when you NEED 180 water to keep the home warm. You don't want to limit the 'top end'. You want it to be able to get that hot IF IT NEEDS TO.

Since the AquaSmart is currently programmed with a High Limit of 190 can I be sure it won't conflict with the Tekmar or would you recommend setting the High Limit even higher on the AquaSmart (like maybe 210? or higher??) just to ensure there is no conflict between the AquaSmart and Tekmar?
You've already got the AquaSmart at 190 and the Tekmar at 180, don't you? That should be enough.

And can the current differential of 20 that is programmed on the AquaSmart stay that way or do I need to change that, as well?
If you feel that changing to a fixed diff of 20 from the previous setting of 'auto' has helped, then try 25 and see how that goes for a while.

The lower the differential, the more often the boiler will fire on an extended heat call... but on the other hand, too HIGH of a diff can sometimes be a problem too. I don't think you can go wrong sticking with 20-25 or so.

Merry Christmas to you and yours as well!
 
  #55  
Old 12-24-13, 01:08 PM
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So if my boiler design temp on the Tekmar is set for 180 degrees on a 0 degree day and my boiler MAX on the Tekmar is set to 190 degrees, that means that 190 degrees is the highest temp the Tekmar can target, correct? So say it got down to -10 or -20 degrees...probably on those days it will target closer to the 190...is that correct? So if the Tekmar does target 190 degrees....and the AquaSmart has a high limit set to 190 degrees....that shouldn't conflict, correct? Just trying to be sure I understand correctly. I guess I was worried the Tekmar would trip on the AquaSmart high limit or something to that effect.

Again, NJ Trooper, thanks for everything.
 
  #56  
Old 12-24-13, 01:37 PM
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Hmmm... and if the AquaSmart IS reading ten higher... I guess you might could bump it up to 200 if you felt it was necessary. I think even if the AS did happen to hit high limit before the Tekmar did it wouldn't really be a problem anyway...

You could think of the AS much the same as one would an 'auxiliary high limit', and when an auxiliary is installed, they are usually set at 200 or even 210...
 
  #57  
Old 12-27-13, 11:35 AM
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NJ Trooper (and anyone else that would like to chime in...),

We had previously discussed the possibility of combining two smaller zones into one as a way to help with short cycling....when you get a chance, could you please elaborate a little more on what is involved in doing that (avoiding costly piping changes, if at all possible)?

The circs are Taco model 007-F5-71FC (it says HP 1/25 AMP .71 HZ 60 volts 115 RPM 3250). Both zones are on the upper floor and there are closed doors between them. The thermostats are less than 25 feet apart.

Thanks!
 
  #58  
Old 12-27-13, 12:26 PM
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Hi Vics...

The difficulty comes in the closed doors between the zones. I presume that these are two bedrooms each on it's own zone?

If the heat loss between them is comparable, it may be possible that one of the two thermostats would be able to signal for heat from both rooms.

Your Taco panel has this spec for each pump switching relay:

All Switching Relays are relay type DPST, have a thermostat current of .18, and have a single phase motor rating per zone of 1/3 hp (7.2A) @ 120 VAC.
So you should be able to safely run several of the 007 pumps from one zone output.

The combining of the zones then becomes a simple matter of disconnecting one of the thermostat inputs to the Taco and doubling up on the pumps to the other zone... moving one or two wires around.

I don't think you ever replied to this... I had a question about zone two:

I see black and white on the ZONE 1 terminals.

I see NOTHING on the ZONE 2 terminals. (unless a wire is hiding in the shadow behind that green wire)

I see a BLUE wire on the "H" terminal of ZONE 3.

Is there a wire on the ZONE 2 "H" terminal?

Do you know which zone is which?
 
  #59  
Old 12-27-13, 03:32 PM
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There is a light blue wire on Zone 2 (it was hiding in the shadow behind the green wire). The circulators are labeled Zones 1 through 4 and say which rooms are in which zone.

So Troop, for any rewiring I take it you recommend I seek out a Master ELECTRICIAN as opposed to a Master PLUMBER? A Master Plumber installed the system (which originally came with the AquaSmart) and another Master Plumber did all the wiring when he installed the Tekmar (ironically, he said he installs "a ton" of them for his clients) so I assume since he did such an amateurish job, a Master Electrician should be able to do better (maybe???????)......
 
  #60  
Old 12-27-13, 03:53 PM
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was it the master plumber himself or one of his helpers?

Some plumbers as well as electricians take pride in their work while others do not...

Most professionals carry a portfolio of their installs with pictures... Sometimes more often then not you can go to thier website to see thier work...


Example.... What do you think the wiring looks like in this taco panel???




credit where credit is due! image courtesy jimgodbout.com
 

Last edited by NJT; 12-27-13 at 04:21 PM.
  #61  
Old 12-27-13, 04:02 PM
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ABSOLUTELY PRISTINE.

A Master Plumber ("old school" kinda guy who has been doing it a really long time) installed the original system (teaching one of his apprentices while installing it). Unfortunately, the AquaSmart was new technology to this guy and he didn't know how to program it to save his life. A different Master Plumber's apprentice/helper installed the Tekmar but the Master Plumber himself checked everything over after the install to make sure it was all good...
 
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