Today I came to Tammys Chestermere home because the master bedroom heating loop is not working again. Last visit about a month ago another tech replaced the zone valve power head. This was done because there are no isolation valves and a cabinet will need to be moved to replace the entire valve. Today we can see that with the power head is better than before and the zone valve gets stuck much less frequently but still does happen intermittently. The whole valve must be replaced. Tammy will wait until later in the year to get this fixed as she can manage it for now.