Tekmar 360 Control- Assistance Needed

I find Tekmar pretty easy to figure out usually. Sometimes there terminology gets in the way

Usually you can find someone that has done a You Tube video on connections or programming. Or at the tekmar site itself.

What are you stuck on specifically?

First step, get all sensors wired, and placed according to what you want them to do.

The boiler sensor location gets confusing. Here are the options for where that gets placed depending on your goals. If boiler protection is your priority, use the first drawing, sensor on the return pipe at the boiler.

I usea small stainless hose clamp. Yes insulation over it. A chunk of fiberglass even if you don't have pipe insulation.

The tekmar sensors have a small dish groove in the sensor so they fasten to pipe well.

You can change and adapt if the system doesn't do exactly what you want the first attempt.

Write down the settings as you make them to keep track of what change makes what difference.

I imagine many controls go in with factor default settings, no one comes back to fine tune it to the exact application. So for the homeowner to learn settings and adjustments really maximizes what the control can do for you.

I just bought an EV truck, it may take the rest of my life to figure out all the settings and options, which they update on a weekly basis!

Just know that some terminals are sensors, some are 24V, and some could be 120V, depending on your wiring choices. So you want to have someone with both 120V and low voltage wiring experience.

A meter is a good idea also to confirm voltages, relay closure etc.

This should be what you boiler control module looks like. Where it shows *thermostat, that is where the Taco 7&8 connect.

Taco has a good wiring guide, for these more involved wiring logics, probably find it online

This drawing. I think all 3 zones have the ability to provide adequate flow for that small boiler, 3 gpm or so. So all you need are 3 zone pumps, which wire to the Taco box.

You don't need or want the circ you show above the boiler.

You can operate 2 pumps off of that #5 contact. According to the diagram L1 and Com (120 VAC) are connected to #3 and #4 respectively.   When #1 and #2 get powered, a set of contacts connect #3 to #5 to operate the pump(s) that are connected to #5 and #6 

If your pumps draw more start amps than the contacts are rated for, you may need an isolation relay.

In many cases you need two pumps when operating a 4 way valve. One is the boiler pump (or heat source pump) and the other is the system pump (or the pump that moves the lower mixed temperature thru the radiator system).

I hope this answers you query

Mr. Ed

@EdTheHeaterMan why not add the DHW priority like this ? Also R4 could have a 120 VAC coil which would eliminate the extra transformer.

@hot_rod asked: "7&8 on the tekmar is a dry contact, where does the boiler TT get closed on this drawing"

@EdTheHeaterMan answered: 7&8 on the tekmar is a dry contact, that's where the boiler TT get closed on this drawing

I looked at using the SR 504 priority zone for the DHW, however using that zone 4 will close the contacts for X X on the Taco SR 504 I believe. In this case, the P1 circulator will operate along with the ODR and Boiler Temperature to make the 4 way valve hunt for a place to settle even with no call for heat from any zone pumps. This may be problematic at times. By leaving the original Tekmar suggested R4 relay for the DHW zone, there should be no problem.

I believe that the high boiler temperature will act as the priority zone based on the way Tom piped the boiler and 4 way valve, without the need for shutting down the low temperature circulators electrically. If there is a call for heat from one or more of the low temperature zones and the boiler temperature to the 4 way valve is somehow reduced as a result of the DHW demand, that lower HOT inlet temperature to the 4 way valve won't matter because the 4 way valve will adjust the MIX temperature based on the MIX sensor.

I told Tom to try it out this way and if there is a problem maintaining enough DHW on the coldest days, then a 3PDT relay can replace R4 DPDT relay in the future. I believe I would then use your idea to connect the DHW aquastat to Zone 4 to make the 1 hour priority protection built into the Taco SR 504 operable. Thanks for that idea! 

Or better yet

you could connect a RIB onto the tekmar box

Many of the RIBs have multi voltage coils giving you options.

If the OP doesn’t have the relay box yet, the Caleffis give you 3 dry contacts, one dedicated to DHW priority

A couple questions, do you have an indirect tank in the piping? Show how you piped it.

Here are two way to properly pipe a 4 way. With a low pressure drop boiler you should not need a boiler loop pump.

If you insist, it needs to pipe like fig 6-12

Is this sketch how it is piped? If so you do not have a boiler loop or pump in it. You look to have a random pump in series with zone pumps. Nothing on the boiler loop

Here they are side by side

@Cyclist77 can you take and post a photo of the front of the boiler from floor to ceiling so I can see how the supply pipe on the boiler is attached to the 4 way valve? The boiler in the center and the DHW on the right and the edge of the plywood with three zone circs on the left

Nevermind

By the time I hit send… it was already there

show the piping from the 4 way on

Boiler piping looks good, is there an air purger up top?

This piping design is as close as I can come to what you have built. There is a possibility that this will work. since this is cast iron, there is no minimum flow needed thru the heat exchanger of the boiler like a ModCon. Thge high limit will keep the boiler from overheating and placing the Boiler Sensor on the return (and setting the dip switch accordingly) will reduce the chance of flue gas condensation (aka: boiler protection) will allow this to operate even if there is minimum flow thru the boiler

I would like to hear @hot_rod' opinion on this design. I believe he mentioned something in a previous post about the P1 circulator being added to the zone circulator pump head. I'm not sure if that is good or bad. He would know better than me.

@hot_rod

Not seeing anything in the Tekmar documentation that supports either of these statements. Not with the Tekmar 360, they show a relay (R1 or R4) added for DHW in each example. And no input (or output) to the Tekmar 360 for DHW purposes. Maybe you are thinking of a different Tekmar product.