Can I use Suunto Comfort Belt with my Suunto t3 or do I need to have t3c?

Yes, you can use Suunto Comfort Belt with your Suunto t3 as well as it will be compatible with Suunto t1, t4 and t6. Pair the Comfort Belt with your heart rate monitor like you would pair the plastic heart rate belt and you are ready to start your training.

Respectively Suunto t1c, t3c, t4c and t6c are compatible with the plastic heart rate belts.

However, it should be taken into consideration that Suunto t1 uses different kind of heart rate belt than Suunto t3, t4 and t6. Suunto t1 has a so called inductive belt whereas Suunto t3, t4 and t6 use ANT-belts. For this reason, for example, Suunto t1 cannot be used with the same heart rate belt than Suunto t4.

See also how to wear your HR Belt and how to change its battery

How can I pair my heart rate belt with my heart rate monitor?

If you replace the HR belt battery or are having trouble with signal reception, you may need to re-pair your belt with your Suunto heart rate monitor.

Option 1
1. Go to "PAIR A POD / PAIR" menu of the heart rate monitor and choose "HR BELT"
2. When text "TURN ON / TURN ON NEW DEVICE" appears on its display, activate the belt by pressing or rubbing both contact pads (electrodes) with moistured palms or fingers
3. In few moments, you should get text "PAIRED / PAIRING COMPLETE" on the display if the pairing has succeeded.

See these pairing instructions also on Suunto TV

Option 2 (by removing a battery)
Please note that Suunto Dual Belt can only be paired with using this option.
1. Remove the battery from the hear rate belt.
2. Reset the belt by inserting the (new) battery positive side down.
3. In your Suunto heart rate monitor, go to the "PAIR A POD / PAIR" menu and select "HR BELT".
4. Put the battery in with the positive side up and press it slightly so that it will have a good contact with the receptors
4. In few moments, you should get text "PAIRED / PAIRING COMPLETE" on the display if the pairing has succeeded.
6. After this close the battery cover.

See these pairing instructions also on Suunto TV

This same procedure can be used if you experience problems with a Suunto POD signal reception.