This Wat Umong Mahathera ChanTemple is often confused with the simple 'Wat Umong" - the one with the tunnels, a little out of town.
Wat Umong Mahathera ChanTemple is another good temple in the old city if you're in the neighbourhood. With so many temples in Chiang Mai, it's not worth crossing town for, but it's as good as many others.
The features here are two very old chedis (stupas), a meditation centre and interesting grounds. When I visited, they were collecting fruit from the many trees in the grounds.
Note that this is directly opposite Wat Pan Ping, so you can visit two good temples for the price of one. They're both close to 'Zoe in Yellow' in case you're looking for redemption.