Arrived onsite to investigate insufficient hot water on a Viessmann combi propane boiler. We tested temperatures at the mixing valve and found 140°F on the inlet and 108°F on the outlet, indicating a failed mixing valve. With the customer’s approval, we replaced the mixing valve along with the scale stopper filter. After the repair, we verified 120°F water at the outlet of the mixing valve. Emailed estimates to perform an annual tune-up and flush the domestic heat exchanger.
