1. Why does the temperature of domestic hot water produced by combination boiler sometimes go up and down?

First，when flow rate of cold and hot water is unevenly distributed, the combination boiler would automatically adjust accordingly.This makes the DHW temperature go up and down or even results in flame out. Therefore, the user is supposed to set the temperature agreeable to them and refrain from turning the tap randomly in order to let the combination boiler settle in a stable working condition.

Second, unstable mains pressure also lead to temperature going up and down.

Third, scald built up in the plate heat exchanger will make DHW suddenly get cold or hot. Therefore flushing and maintenance after several years of operation become very necessary.

2. What is the appropriate water pressure for combination boiler?

Combination boilers runs normally when the water pressure ranges 1.0-2.0 bar. When the water pressure gets below 1.0 bar, the unit starts refilling. It drains when water pressure goes above 2.0 bar.

3. How to set the temperature user feel comfortable ?

In addition to climate difference and insulation of buildings, actual ambient temperature and personal preference for heat should be taken into account when setting temperature. The vast majority of healthy people, when dress appropriately and are in a quiet state, the indoor temperature will be more comfortable at 20℃ and the human body will not feel cold at 18℃, but obvious coldness would be felt at 15℃. Therefore, the most comfortable heating temperature in winter is set to 18℃±2℃.