Contender & Tekmar TN4

Unknown

Vision 1 can do this without a relay.

In tekmar land, the 420 can do this if you don't have to run a mixing device (that is, if you are only using one water temperature for heating, not counting DHW). You'll need a tekmar interface card on the munchkin as well, and a 335 or a 336 zone controller.

If you are ONLY looking to do DHW priority, use the vision 1.

If you are looking for a fully integrated heating system, use the tN4.

mikea23

Looking for a

wiring strategy where I can utilize the Munchkin 0-10 volt interface and a Tekmar TN4 420 Boiler reset. I'd like the 420 to control the Modulation of my contender for both heating and domestic hot water loads. I've have cheated in the past and used a rely and aquastst to allow the munchkin to control domestic hot water production.
Thanx in advance.....

Guy Woollard

Simple

That boiler will modulate all by itself, so adding modulating logic is rather redundant. Even on the domestic water side, the control logic will still modulate, so I guess that I don't see the gain that you are trying to get.

Guy Woollard
N.E. Regional Sales Mgr
Triangle Tube Corp.

Uni R_2

Tekmar SB

http://www.tekmarcontrols.com/sb/sb037.pdf

mikea23

Thanks!

Thank you Uni R.
Have you had good luck with the Munchkin and TN4 controls?

Uni R_2

No experience with either...

But that combination was considered last fall when I was looking for a new system.

I really like the TN4. Consider the 422 if you think you'll need to control a second temperature circuit.

Steve_151

you'd go with a 422

over a 420 and Use the "External TN4 Control Mix 2 Temp" to Ramp up the Contender for faster Domestic Hot water production?

Steve_151

so you'd go with a 422

> But that combination was considered last fall

> when I was looking for a new system.

>

> I really

> like the TN4. Consider the 422 if you think

> you'll need to control a second temperature

> circuit.



over a 420 and Use the "External TN4 Control Mix 2 Temp" to Ramp up the Contender for faster Domestic Hot water production?

Steve_151

so you'd go with

a 422 over a 420 reset module and Use the "External TN4 Control Mix 2 Temp" to control the second water temperature to Ramp up the Contender for faster Domestic Hot water production? Could you use a Universal 10K sensor in the indirect well in place of a mechanical aquastat?

Unknown

tN4 will give the boiler indoor feedback with which to control the modulation, so it can modulate up or down depending on what's actually happening in each zone, not just based on outdoor temperature. So if a user turns up a tstat, the system can bump up the temp to react faster, then settle back down.

This indoor feedback will also minimize water temps and eliminates the need to set munchkin parameters to make it work while sacrificing the bottom end of the reset curve. This also results in a lot better operation in the zones.

Finally, tN4 will do zone syncronization to reduce cycling under lower loads.

Tn4 basically blows the on board electronics out of the water, especially for a radiant system. it's hardly redundant.. it's a whole new set of capabilities and intelligence.

That said, I have no idea how to interface with a contender, haven't used it yet but Vision is a thing of the past around here except when budget is very tight.

Steve_151

hydronicsmike.... maybe you could shed some light?

What I'd like to do is get the boiler reset module to high fire the Munchkin (Preferable through the 0-10 volt interface) when there's a call for domestic hot water, purge, and then resume space heating at a low water temperature.
With out using a relay, which is how i have accomplished this in the past......
is the 422 or 423 the right module for this with the two water temperatures?
I'd love to use a simple sensor in the aquastat well to call for DHW on a TN4 boiler reset

Theealchemist

That hydronics mike

is the best!!
Thanx Mike!

Theealchemist

NRT

Thanx for the reply. I'm a big fan of yours.
So..... I am running only one temperature for heating. I have the Tekmar interface board installed on the Munchkin to the 420 boiler reset. The 420 is mated with a 335. I'm looking for a TN4 fully integrated system. Hence the 420/335 combo. Not Vision. Don't get me wrong i like the vision platform but I'm hooked on TN4. My problem is the Contender doesn't fire at it's full Modulation when there is a call for DHW. At first i just switched between vision and Tekmar via a switching relay with my older munchkin installs and TN4 systems. I want to do away with the relay.......

Unknown

Hmm, not sure. might need to check with tekmar and make sure you have it wired correctly.. there should definitely be no need to switch to vision for this.

Here is a detail for a 420 doing DHW on a munchkin.. not a contender, but maybe that part is the same?

scott markle_2

dhw

The 420 operates with a 10k sensor for dhw production. The bioler will modulate based on proximity to tank target temperature. Unlike an aqustat which will run boiler at full output until contact opens. The sensor mode is preferable in that it avoids target overshoot and maximizes low output condensing efficiencies. As far as the boiler is concerned it fires based on the variable voltage signal it receives, dhw, setpoint, heat, it dosen"t distinguish. The 420 determines what circulators are running etc. based on mode of operation.

Theealchemist

A Big Thank you....

To Chuck Shaw From Heat Transfer Products and Mike Miller from Tekmar controls. Two great guys that know a hell of alot about their products!

Theealchemist

Good To Know

Thanx for the heads up scott. I'd much rather use a well sensor than the aquastat.

Theealchemist

Aquastat or sensors

which do you usually like to use to control your indirect NRT?
Looks like an aquastat on your drawing.

Unknown

well, maybe we're wrong, but to the best of our knowledge only the 423 can take a sensor for DHW, the 420/422 only take on/off signals from an aquastat.

If we can use a sensor, we will.

scott markle_2

sensor vs. on-off dhw

I gave some misinformation, In the tn4 line only the 423 can use a dhw sensor. Seems a shame this is not an option on all the tn4 boiler controls.