AC/Heat control upgrade

I am the happy owner of a 2007 Country Coach Magna 620 with aVMS240 with the recent upgrade to a HMS360 display and iPhone app control. I now have the ability to monitor and control many functions via the remote app and would like to expand this to control the three zones of heat and AC with the remote app as well.
What will it take to connect the three AC/heat pumps as well as the Aqua Hot which are currently controlled by the Coleman thermostat?

Magna with HMS360 ready for upgrades

Pencil in two 'black boxes' and wiring to make this happen.
Very doable though not without a bit of tedium.
Expenses to convert this from 'penciled' to 'inked':
TM220 $249
TM225 $249
Multi-point (6-way) RV-C tap $24
Wire and hardware $100? (less than that most likely)
Temp sensors x3
reProgramming TM102: $50**
Labor: significant.

**This would cover any special settings on either the TM220 or TM225 as well.

The ACs, if Dometic with a data-link, are going to be a bit tricky. Currently, their wiring goes to one place and they're linked, otherwise, together. However, we'll need pair of wires to each of the ACs' controller-circuit board, inside each AC, ran to the TM-220. The TM220 may be stowed a couple 'convenient' places but, lets just arbitrarily say (for this chat) that it ends up near the HMS or bath/hall interior wall. This means one pair of wires from each AC must be fished through the plenum and down to the TM220. Also, a temp sensor needs to be ran to said box also. So, sensors x3 must be strategically placed with their pair of wires ran into the TM220. I don't believe there's existing sensors to reuse.

If its the simpler non-Dometic (without the data-link and just using the spring-switch thermostat) things get a bit simpler. The wire runs are then from the thermostat to the TM220 I believe.

For the Aquahot you'll use a TM225, a similar unit programmed for this purpose. The wiring needs are similar to the other unit. Take a look HERE to get a glimpse of what these look like.

Once those units are wired to their respective heat/cool/Aquahot units, a run of 4 wires (2 for data, 2 for power) are then ran for each to the nearest RV-c connection, near the HMS or most anyplace you can 'tap in.' We'd need to reprogram your TM102 to account for the larger census. At that point then you'd have 'app' control of these units.

This is about what it would take.


Art Renda
Documentation Central
Silverleaf Electronics
(888) 741-0259

AC/Heat Control upgrades- add'l questions

Thanks so much for all the info-
The 3 roof top units are RVP 15000 but heat pump units model#9024-876. Do you happen to know if these are the "simpler" non- data link units that would require simpler wiring from the TM-220 to the thermostat? There are three temperature sensors in the coach- one for each zone. I have attached a picture of the two wire white plastic sensor here:


If the 9024-876 units area simpler and the sensors already exist would this be a easier install?

More sensors?

Is 4 outputs and 4 sensors enough for the level of control? I'm thinking we would need 5 temperature sensors? Can this be accomodated easily? Sorry - very inexperienced and a bit at the deep end here.

Numbers of sensors

Hello Paul

There's a sensor and control 'leg' for each roof top unit. Usually there's 3 or 4. In specialty coaches with 5, we add a box. Though it doubles the capacity to 8, its usually just for the 5th unit.

All questions are welcome here--its how we all learn the ropes.