What to do to avoid an increase in pressure in the cold water circuit

There is a problem: we replaced the water supply system, put a comb on Rehau Stabil pipes with pressure regulators. The pressure in the cold water circuit rises, similar to heating. All that was possible was isolated, but the pipes go in a bundle very close to each other, cold and hot. The pressure rises from 3 to 6 atm in two hours, when you start up the hot one, maybe faster. Tell me, what can I put into the system to fix the problem - an expansion tank, a safety valve or protection against water hammer type VT.car19? The volume of water in the pipes is approximately 2-3 liters (12 meters Rehau 16 mm).

Sergei

Expert Answer

Sergey, the factors you described indicate a mixture of hot water in the cold circuit. The fact that in your water supply system pipelines are laid at a minimum distance from each other has nothing to do with it. Such troubles most often occur with a malfunctioning or malfunctioning consumable device - a mixer, a water heater, etc.
As in the tee water distribution system, in the collector wiring, liquid overflow in parallel lines can be eliminated with the help of check valves. Moreover, it is not necessary to install locking devices on each circuit - it is enough to use them in the places where consumables are connected, using both hot and cold water. These points include a water heater, faucets, washing machine or dishwasher, etc. As a rule, after such an upgrade, the pressure in the system circuits stabilizes.