Tekmar 260 help for amateur

Reply

  #1  
Old 07-16-13, 08:20 AM
marriott's Avatar
Member
Thread Starter
Join Date: Jul 2013
Location: USA
Posts: 24
Received 0 Votes on 0 Posts
Tekmar 260 help for amateur

Hi,
I am new to the forums and to homeownership.

I'm having issues with my 1 year old heating system.

Some info about it: Buderus oil fired boiler with HTP indirect fired water heater. These are hooked up to a Tekmar 260 which also has a Taco ZVC403 zone valve control plus 3 Honeywell zone valves, one of which controls the indirect water heater.

Ok, now to the issue: the boiler isn't heating up the water for the water heater even though the heater is calling for it(I know this because the lights on the ZVC403 indicate this and the honeywell valve thing is open and really warm to the touch).

The problem happens during warm weather more so than cold weather. This leads me to believe that there is something in the Tekmar 260 that needs adjusting.

I am wondering if changing the DIP switches to DHW priority and DHW during UnOCC will remedy the problem?

I don'tknow whether to have the switch on DHW Valve or DHW Pump?

Or perhaps I am way off in my assumptions about the cause of the problem.

Any sugestions(in layman's terms) would be greatly appreciated.
Thanks!
 

Last edited by NJT; 07-16-13 at 03:09 PM.
Sponsored Links
  #2  
Old 07-16-13, 03:05 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 2 Votes on 2 Posts
Setting DHW priority won't do much during a 'non' heating season call for DHW. What the priority does is holds off any space heating calls during a DHW call in order that the boiler may give full attention to the domestic water heater.

DHW during UNOCC won't do anything for you either. The 260 has provision to add a timer for OCCUPIED and UNOCCupied 'setback'. This setting would prevent DHW calls during times the home is not occupied. You didn't say whether or not you have such a timer, and I suspect that you do not, so the setting is probably moot.

You want the switch set to DHW VALVE, since that is how your system is set up, with VALVEs, and no discrete pump for the DHW. (at least from your description, that is my understanding. You do NOT have more than 1 pump, is that correct?)

The LEDs on the 403 panel : Do BOTH the YELLOW AND THE RED LED light when the DHW is calling for heat?

If only one LED lights, the problem is with the zone valve.

A little bit about the zone valve operation...

Inside there is a motor that opens and closes the valve itself. When the 403 panel gets a signal from a thermostat (or the DHW), it will send 24VAC to the motor.

When the valve is fully open, there is a cam inside the valve that operates a small 'microswitch'. When this switch closes, it tells the 403 that the valve is open and to go ahead and fire the boiler.

The 'disconnect' is probably the fact that this switch isn't working properly... a COMMON problem.

The hypothesis can be tested easily if you own a multimeter and know how to use it. Do you?

OR, you could drop about $60 or so and replace the power head on the valve (If it's the 'new style' power head, this is easy. If it's the OLD style, it means the system will need to be drained.)

Tell me the model of the zone valves you have. Look for a number that starts with the letter " V "
 
  #3  
Old 07-16-13, 03:24 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 2 Votes on 2 Posts
I just thought of another possibility...

Your system might not be wired properly. The Tekmar 260 may not realize that the heating call is a DHW call if not correctly installed. If this is the case, the boiler may be in WWSD (Warm Weather Shut Down).

Can you describe to your best ability how the system is actually wired?

In particular, are there wires going to terminals 3 and 4 in the 260? If so, where are they coming from?

Pictures are sometimes hard to follow for electrical wiring, but if you can get good clear hi-res pics of the wiring it may help us help you.
 
  #4  
Old 07-19-13, 05:04 PM
marriott's Avatar
Member
Thread Starter
Join Date: Jul 2013
Location: USA
Posts: 24
Received 0 Votes on 0 Posts
Thanks for replying so quickly! I ruled out the faulty honeywell valve as the culprit, because it cools down and the lever thing goes back to the right once the hot water tank has been filled (which is around 2 a.m. with the hot weather we've been getting). I checked out terminals on the 260 and the 3 and 4 are empty of wires. I may have left out potentially useful information: there is also a beckett aquasmart 7600 that all the wires go into after going through the taco and tekmar. I checked the domestic hot water priority on that(aquasmart) it says "on zr".
Is this a problem that I culd potentially fix with the flip of a switch or changed setting? If no, I am more than happy to pay a professional fix it.
Thanks again NJT, I hope you are properly compensated for all the advice and help you give people
 
  #5  
Old 07-19-13, 05:45 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 2 Votes on 2 Posts
Hi Marriott,

I'm afraid that without being there to see how the whole thing is wired, any attempt to troubleshoot over the 'net will be frustrating and futile. That's how it is with wiring...

I checked out terminals on the 260 and the 3 and 4 are empty of wires...

I checked the domestic hot water priority on that(aquasmart) it says "on zr".
This tells us that the 260 is clueless whether or not the DHW is calling for heat.

The Aquasmart _may_ be able to overcome this if it's wired correctly. It's looking for a signal from the system that there is a DHW call by monitoring the "ZR" terminal. Take a peek inside the A'Smart and see if there is a wire on the "ZR" terminal.

Is this a problem that I could potentially fix with the flip of a switch or changed setting? If no, I am more than happy to pay a professional fix it.
No, not likely a flip of a switch is going to help. It is also unlikely that you will be able to find a 'professional' with the skill set required to diagnose and properly wire the system. REAL technicians are few and far between these days. I would venture to say that if they even try, they will F it up worse. Your mileage may vary, and I wish you luck!

I probably could sit down and draw up a diagram of how it could be wired so everything plays together properly, but I sense that you may not have the skill set to take that wiring diagram and 'make it so'... is that a fair statement? (no offense intended of course!) Tell me if I'm wrong and I'll see what I can come up with.

Thanks again NJT, I hope you are properly compensated for all the advice and help you give people
You're quite welcome... only compensation I get is the satisfaction of 'paying it forward'. All the mods here are volunteers.
 
  #6  
Old 07-19-13, 05:57 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 2 Votes on 2 Posts
Let me ask a few more questions, because there may be a 'band-aid' solution that could possibly consist of a few button pushes...

When the DHW tank calls for heat, does the BURNER in the boiler actually FIRE?

I believe you are going to say "Yes, it does", and if this is the case, then you are probably correct that the Honeywell zone valve is not at fault.

When the DHW is calling for heat, have you noticed the reading on the boiler TEMPERATURE GAUGE?

My suspicion at this point is that the boiler temperature is low due to the 260 'setting back' the boiler temperature because of the hot weather, and not knowing that the incoming heat call is for the DHW.

On systems such as yours which have "Outdoor Reset" (the Tekmar 260 is just that), there must be a way for a DHW call to over-ride the temperature setback.

That is the purpose of the "DHW demand" input to the 260.

If the boiler is not being allowed to get the water hot enough, the result will be EXTREMELY LONG recovery times for the DHW tank... I think this is what is happening after reading your last post.
 
  #7  
Old 07-20-13, 06:46 AM
marriott's Avatar
Member
Thread Starter
Join Date: Jul 2013
Location: USA
Posts: 24
Received 0 Votes on 0 Posts
It is a fair statement to suggest I would not know what to do with a wiring diagram(I'm a cook by trade). Just looked in the aquasmart and the zr terminal has no wire connected to it. (This makes me wonder about the person who installed the system!) The burner in the boiler will not always fire when the DHW is calling for it to.Yesterday the burner fired up, making me excited that I'd be getting some hot water, but it didn't heat up the water for the tank. The DHW has been calling for hot water for about 24 hours. The Aquasmart says the temperature of the boiler is 161 F and the gauge reads a little above 140 F.
 
  #8  
Old 07-20-13, 06:56 AM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 2 Votes on 2 Posts
The two pipes leading to and from the water heater from the boiler...

When the DHW is calling for heat, and the boiler temp says it's at 160 (your gauge may be defective?), are you able to feel the hot water in the pipes? Carefully put your hand on the pipes and 'follow the heat'.

You should be able to heat up the DHW tank with 160 water... 140 less so, but it certainly should NOT be calling for 24 hours!

I'm wondering if the pump is pumping... I bet it's not.

If you have a decent camera why not take some pics... a whole bunch... as well lighted and in focus as possible... and let us see what you are working with? Even if you don't want to tackle it yourself, we can probably at least guide you with a bit of information.
 
  #9  
Old 07-21-13, 06:29 AM
marriott's Avatar
Member
Thread Starter
Join Date: Jul 2013
Location: USA
Posts: 24
Received 0 Votes on 0 Posts
photos of boiler system

marriott3k's Library | Photobucket
 
  #10  
Old 07-21-13, 06:49 AM
marriott's Avatar
Member
Thread Starter
Join Date: Jul 2013
Location: USA
Posts: 24
Received 0 Votes on 0 Posts
Here are some pictures I took of various parts of the boiler. Let me know if you want closeups of certain things.
Yesterday, after being without hot water for 36 hours, I decided to change some things on the tekmar 260. Went into advanced mode on the DIP switch, pressed the item button until it was on the WWSD OCC and changed the temp from 70 F to 80 F. The boiler fired up a few minutes later and I have hot water, for now. This doesn't seem like the ideal way to get hot water, but it is a band aid, assuming that the change in the WWSD temp was what fired up the boiler.
 
  #11  
Old 07-21-13, 08:13 AM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 2 Votes on 2 Posts
That helps a lot, thanks.

I can tell you that it's not wired properly.

Your controls aren't 'playing well' with each other. It could be that the WWSD is kicked in. This will prevent the boiler from firing whenever the outdoor sensor is above the WWSD temperature. You could even kick it higher, because when the outdoor temp goes above 80, it won't work again. In your case, I would in fact turn the WWSD setting to OFF. Yes, that's right, OFF. It is not really needed for your installation. It's real primary purpose in my opinion is to prevent tenants in a multi-occupant building from calling for heat when it's not needed. Unless one of your family members pushes a thermostat way up, you won't notice any difference in operation.

This still will NOT be the ultimate solution, because in addition to WWSD, the control is also lowering the temperature of the boiler water such that it won't be hot enough to reheat the tank in a timely manner.

You may be able to TEMPORARILY (for the summer only) change some other settings that will allow the boiler to get up to temperature and heat your water. More on that a bit later...

The way it is currently wired, the "DHW VALVE / DHW PUMP" along with any of the other DHW settings on the 260 are moot, because the 260 doesn't have a clue that there is a DHW connected. (no wires on the DHW DEMAND terminals).

When the 260 is wired correctly so that it 'knows' it is receiving a DHW call, it will over-ride the WWSD and the boiler temperature setting in order that the DHW can work properly and these settings can be returned to normal and left alone summer/winter.

cont'd...........................
 

Last edited by NJT; 07-21-13 at 08:40 AM.
  #12  
Old 07-21-13, 08:15 AM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 2 Votes on 2 Posts
ASIDE FROM the DHW problem, I would also like to address what may be another issue:

I would like to see a picture of the flue pipe from the boiler to the chimney. It doesn't look as if you have a 'barometric damper' installed, and I believe that you should have one. I need to look at your boiler manual to be certain... what is the full model of the boiler ?
 

Last edited by NJT; 07-21-13 at 08:35 AM.
  #13  
Old 07-21-13, 08:32 AM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 2 Votes on 2 Posts
Other control settings that are moot the way your system is installed:

ROOM temperature, either OCC or UNOCC

Because you have neither an "INDOOR" sensor or an OCC/UNOCC timer installed. The control will always be in the OCC mode, and without the indoor sensor, the control can't and won't adjust for this. Indoor sensor is an alternate way of providing control and occ/unocc room temperature 'setbacks'. Both of these items are optional and may be added (or not) at any time.

Now on to other settings that may improve your DHW problem TEMPORARILY, until wiring changes can be made, and also for 'sanity checks' of the current settings.

Record and report the following 260 settings:

OUTDR DSGN =

Terminal Unit =
(this should correspond to the type of heat emitters in your home. Fin-tube baseboard is 4)

BOIL DSGN =

BOIL MAX =

BOIL MIN =

BOIL INDR =
(this will probably be set to 70, and should be left there. If set unreasonably high or low by someone, return it to 70)

FIRE DLY =

BOIL DIFF =
(in most cases this will be set to " Ad " for AUTO DIFFERENTIAL, let the control decide setting based on conditions it knows about)
 

Last edited by NJT; 07-21-13 at 08:56 AM.
  #14  
Old 07-21-13, 08:50 AM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 2 Votes on 2 Posts
I see something else weird in the pic of the 260 wiring.

On terminals 1 and 2 it appears that there are 12 or 14 gauge regular 120VAC house wiring going to them.

Trace these wires and tell me where they are going to/from.

BE CAREFUL! 120VAC EXPOSED INSIDE THAT BOX! DON'T TOUCH THE WIRES! YOU CAN BE KILLED!
 
  #15  
Old 07-21-13, 08:55 AM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 2 Votes on 2 Posts
By the way... if I ask a question, it means I need an answer in order to properly diagnose... I will usually BOLD my questions that require answers... so don't 'blow by' them because it will help me to help you.
 
  #16  
Old 07-21-13, 10:01 AM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 2 Votes on 2 Posts
More questions, and maybe another picture...

In the ZVC403 panel, what wires are on the ENDSWITCH terminals, and where do they go?

Are there any wires on the " NO COM NC " terminals, and if so, where do they go?


What I'm going to try and do is come up with a 'fixed' wiring diagram that you may be able to find someone to make the changes for you. In order to do this though, I need to know EXACTLY how it is currently wired, and why I'm asking all these questions.

You may even be able to make the changes yourself, they should not be too difficult... we're here to guide you.
 
  #17  
Old 07-22-13, 06:43 AM
marriott's Avatar
Member
Thread Starter
Join Date: Jul 2013
Location: USA
Posts: 24
Received 0 Votes on 0 Posts
Model of boiler: Buderus Logano G115 WS 6720615225
OUTDR DSGN:0
Terminal Unit:6
Boil DSGN: 180
Boil Max:200
Boil Min:140
Boil INDR:70
Fire Dly: 10 min
Boil Diff: AD

Trace wires from terminals 1 and 2 on the 260, where do they go?:
The white wire in terminal 2 goes into a gray endcap with 4 other wires in it.

Those wires go:

One goes up into the left side of ZVC403(THe section isn't labeled, the instruction sheet says it's a factory installed transformer, maybe) and is tied in an endcap with another white wire.

Another one goes into termonal 6 on the 260.

Another one goes up into a red circle with a black button above the boiler(Emergency shut off?),
which then goes down into the Guard Dog low water cut off and
then into the Aquastat

The black wire on terminal 1 goes into a yellow endcap with other black wires.

Are there wires on the ZVC403 endswitch terminals:
Yes

The black wire goes into the tekmar and into the yellow endswitch.

The white wire goes into the 260 where it is connected to a black wire with a red endcap.

That black wire goes into a gray endcap with 3 other black wires.

They go:

one goes up to the ZVc403 left side transformer thing connected to another black wire.

Another goes to terminal 5 on the 260.

The other goes into that red circle with a black button above the boiler(Emergency shut off?),
which then goes down into the Guard Dog low water cut off and
then into the Aquastat.

There is a green wire below the endswitch terminal that doesn't go to anything.

Are there wires on the "NO COMM NC"?
No, there are not.

I will post a link to a photo of the inside of the ZVC403.
Thanks NJT!!
 

Last edited by NJT; 07-22-13 at 02:33 PM.
  #18  
Old 07-22-13, 06:50 AM
marriott's Avatar
Member
Thread Starter
Join Date: Jul 2013
Location: USA
Posts: 24
Received 0 Votes on 0 Posts
photo of ZVC403

 

Last edited by NJT; 07-22-13 at 02:27 PM.
  #19  
Old 07-22-13, 07:12 AM
marriott's Avatar
Member
Thread Starter
Join Date: Jul 2013
Location: USA
Posts: 24
Received 0 Votes on 0 Posts
Photo of chimney

 

Last edited by NJT; 07-22-13 at 02:27 PM.
  #20  
Old 07-22-13, 03:21 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 2 Votes on 2 Posts
I'm going to go with one question per post to make this easier, answer in separate posts please so I can keep it all straight in my haid:

You said:

Terminal Unit:6
What type of 'terminal units' do you have?

Setting 6 is typically for CAST IRON baseboard. This is not a very common baseboard. Do you know if this is what you have?

Take a flashlight and look inside your baseboard. Do you see a copper tube with aluminum fins on it? This is MUCH MUCH more common. If so, change this setting to FOUR ( 4 ).

Take a picture if unsure.
 
  #21  
Old 07-22-13, 03:27 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 2 Votes on 2 Posts
Another one goes up into a red circle with a black button above the boiler(Emergency shut off?),
I believe this is a fire detector that will shut off the boiler if there is excess heat.

Is there ANOTHER cable coming out of this box and going to ANOTHER switch with a red plate on it? Perhaps at the top of the stairs, perhaps labeled "Emergency Shut Off" or some such?

In other words, in ADDITION to the cable from the 260 and the Guard Dog, is there is ANOTHER cable coming from 'somewhere' other than the boiler controls?

I want to establish where the power from your circuit breaker panel is coming into the system.
 
  #22  
Old 07-22-13, 03:31 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 2 Votes on 2 Posts
You said, referring to the 260:

The black wire on terminal 1 goes into a yellow endcap with other black wires.
How many 'other' black wires are in this endcap?

Where do the 'other' black wires go?

Then you said:

The black wire goes into the tekmar and into the yellow endswitch.
Do you mean that this is one of the 'other' black wires in the yellow endcap in the 260?
 
  #23  
Old 07-22-13, 03:36 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 2 Votes on 2 Posts
I wanted to see the entire flue pipe from the boiler to the chimney.

Don't take any more pics of it though, just tell me if there is a TEE on the pipe with something that looks like this installed in the TEE fitting:


image courtesy fieldcontrols.com
 
  #24  
Old 07-22-13, 03:38 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 2 Votes on 2 Posts
I know this is tedious, but trust me that we have come a LONG way in determining the problem. I'm very close to being able to propose a solution.

Funny thing is... if I could just be there to SEE it, it would all be sussed in about a half hour. Doing wiring over the internet is a beeotch!

Is my lobster ready yet?
 
  #25  
Old 07-22-13, 03:39 PM
marriott's Avatar
Member
Thread Starter
Join Date: Jul 2013
Location: USA
Posts: 24
Received 0 Votes on 0 Posts
Yes, there are 2 other large white cables going into that fire detector above the boiler, one of which goes towards the top of the stairs, I presume to that emergency switch, and the other one goes into the circuit breaker. The cables say they are 600 V if that matters.
 
  #26  
Old 07-22-13, 03:40 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 2 Votes on 2 Posts
Yes, there are 2 other large white cables going into that fire detector above the boiler, one of which goes towards the top of the stairs, I presume to that emergency switch, and the other one goes into the circuit breaker. The cables say they are 600 V if that matters.
Excellent! Getting closer!
 
  #27  
Old 07-22-13, 03:56 PM
marriott's Avatar
Member
Thread Starter
Join Date: Jul 2013
Location: USA
Posts: 24
Received 0 Votes on 0 Posts
Yeah, that is one of the black wires. It was a repeated statement. Let me go and make sure there are a total of 4 black wires in that gray endcap: Yup, there are 4 wires. One goes into the endswitch of the ZVC403, one goes into the ZVC403's transformer(at least that is what I think it is) one goes into terminal one on the tekmar 260 and the last one goes into that red fire detector above the boiler.
.
 
  #28  
Old 07-22-13, 04:00 PM
marriott's Avatar
Member
Thread Starter
Join Date: Jul 2013
Location: USA
Posts: 24
Received 0 Votes on 0 Posts
No, there's nothing that looks like that on the flue pipe.
 
  #29  
Old 07-22-13, 04:07 PM
marriott's Avatar
Member
Thread Starter
Join Date: Jul 2013
Location: USA
Posts: 24
Received 0 Votes on 0 Posts
Oh , and I changed the terminal unit to 4 because i have those aluminum fin baseboard heaters.
 
  #30  
Old 07-22-13, 04:24 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 2 Votes on 2 Posts
Yeah, that is one of the black wires. It was a repeated statement. Let me go and make sure there are a total of 4 black wires in that gray endcap:

Yup, there are 4 wires.

One goes into the endswitch of the ZVC403,

one goes into the ZVC403's transformer(at least that is what I think it is)

one goes into terminal one on the tekmar 260 and

the last one goes into that red fire detector above the boiler.
Yes, correct, that is a transformer in the 403.

But... confusing me again...

You also have a YELLOW and a RED endcap (aka WIRENUT ) in the 260.

one goes into terminal one on the tekmar 260

Terminal ONE in the 260 doesn't go into the YELLOW wirenut and then to the endswitch on the 403? Are there OTHER wires in that YELLOW wirenut? If so, where do they go?

What happened to terminal FIVE?

One goes into the endswitch of the ZVC403,

But first goes into the RED wirenut, and then a WHITE wire goes to the endswitch of the 403?
 
  #31  
Old 07-22-13, 04:48 PM
marriott's Avatar
Member
Thread Starter
Join Date: Jul 2013
Location: USA
Posts: 24
Received 0 Votes on 0 Posts
Confused

I'm really confused, it's me, not you, promise! So, went back to take a look and the 4 black wires in the gray wire nut go to:::: one goes to terminal 5 in the 260, one goes to the aquastat/round red fire detector one goes to the transformer in the ZVC403 and the other one is red wire nutted to a WHITE wire coming from the endswitch in the ZVC43. The yellow wire nut has black wire coming from endswitch inhe ZVC403 to terminal 1 in the tekmar 260
 
  #32  
Old 07-22-13, 04:57 PM
marriott's Avatar
Member
Thread Starter
Join Date: Jul 2013
Location: USA
Posts: 24
Received 0 Votes on 0 Posts
Attachment 15470
Here's your lobster.
 
Attached Images  
  #33  
Old 07-22-13, 05:04 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 2 Votes on 2 Posts
OK, good... I think that's what you said the first time...

Getting closer!

I'm gonna quit soon for the night and enjoy my Lobster, THANKS!

I need to check with tech support at Tekmar, but I believe that the solution is possibly going to be as easy as running two thin thermostat wires from the 403 to the 260... like 5 minutes work maybe.

Have you got any short pieces of that thin thermostat wire laying around?
 
  #34  
Old 07-22-13, 08:44 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 2 Votes on 2 Posts
This is, I believe, your 'as wired' system:



Please check over very carefully to make sure it's all correct.

I have to think about the changes needed, hopefully it will be as easy as I suspect.

Full size drawing here:

marriott2_zpscd03cd20.jpg Photo by JeffPicks | Photobucket
click magnifying glass at lower right... once... twice... for largest size
 
  #35  
Old 07-23-13, 07:11 AM
marriott's Avatar
Member
Thread Starter
Join Date: Jul 2013
Location: USA
Posts: 24
Received 0 Votes on 0 Posts
Wow, that's really great! It looks right. The only difference is the black and white wire below the ZVC403 transformer are each tied together with a yellow wirenut. Does that make any real difference?
 
  #36  
Old 07-23-13, 07:15 AM
marriott's Avatar
Member
Thread Starter
Join Date: Jul 2013
Location: USA
Posts: 24
Received 0 Votes on 0 Posts
I could do 5 minutes of work, especially since it may not involve the larger,more deadly wires! I don't have any thermostat wire lying around. I could get it at a hardware store, right?
 
  #37  
Old 07-23-13, 02:38 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 2 Votes on 2 Posts
It looks right.
Good... but just to be absolutely certain... there are NO OTHER WIRES in either the RED or the YELLOW wirenuts, CORRECT?

The only difference is the black and white wire below the ZVC403 transformer are each tied together with a yellow wirenut. Does that make any real difference?
No, not at all... I just drew them as direct connections because space was tight up there.

since it may not involve the larger,more deadly wires!
You are going to be TURNING OFF THE POWER TO THE BOILER before you stick yer burger flippers in there!

I could do 5 minutes of work, especially since it may not involve the larger,more deadly wires! I don't have any thermostat wire lying around. I could get it at a hardware store, right?
You can buy thermostat wire by the foot at Home Depot or Lowes. You're only going to need 2 feet or so. You only need the 2 conductor stuff... but if all they have is 4 or 5 wire, get it anyway. Just use 2 of them and cut the others short.

I'm ready to draw in the two wires you will be adding. I need to know which 'channel' of the 403 you have the indirect water heater connected to so I can put the wires in the right place.
 

Last edited by NJT; 07-24-13 at 04:20 PM.
  #38  
Old 07-24-13, 04:27 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 2 Votes on 2 Posts
Reply from my 'guy' at Tekmar is that this will work.

Here's how it works:

When DHW calls for heat, the 403 energizes terminals 1 & 2 with 24VAC to power the motor in the zone valve.

The 260 will sense this 24VAC on the DHW DEMAND terminals and respond by over-riding any temperature setbacks, WWSD, etc that the 260 might be using for space heating. It will allow the boiler to fire to it's high limit setting of 180F. This will give you fast, uninterrupted, operation of the water heater.

I drew these two wires on 'channel' 3 of the 403, but if your DHW is wired to a different channel just connect the wires to terminals 1 & 2 of that channel.

I 'trimmed' all the other wires from the first drawing for clarity. All the other wiring remains UNCHANGED.



On the 260, DHW must be set to VALVE or else the pump will not run when DHW calls.

You will NOT be able to set DHW PRIORITY in the 260, you will get an 'error code' if you try.

If you need DHW priority (most installs do not... I'm quite sure yours is no exception) you MAY set priority in the 403 panel. For now, leave it OFF.
 

Last edited by NJT; 07-24-13 at 04:43 PM.
  #39  
Old 07-24-13, 04:46 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 23,539
Received 2 Votes on 2 Posts
Just to re-cap this issue for future readers:

The reason the DHW was not working properly is because the Tekmar 260 had no way of 'knowing' that the call for heat coming in was for the DHW. As far as it knew, it was just another call for space heating.

Adding those two wires allows the 260 to distinguish between a DHW call and a space heating call and respond appropriately.
 
  #40  
Old 07-25-13, 04:28 PM
marriott's Avatar
Member
Thread Starter
Join Date: Jul 2013
Location: USA
Posts: 24
Received 0 Votes on 0 Posts
That looks do able

I promise I will turn the power off before attempting this. Will let you know how it comes out. (You must be psychic because the indirect water heater is on channel 3.) Thak you so very much for taking the time to help me through this.
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes
 
Ask a Question
Question Title:
Description:
Your question will be posted in: