Perhaps the reason is that the mixer is spoiled or locked. If you do not know how to fix this, I would recommend you call professional plumbing or order a service https://pomplumbing.ca/mixing-valves-adjustment-maintenance-and-repair/. Another reason may be a lack of water in your system. In this case, I would recommend checking that in your city or settlement there is enough water for delivering to your house.
Perhaps the reason is that the mixer is spoiled or locked. If you do not know how to fix this, I would recommend you call professional plumbing or order a service https://pomplumbing.ca/mixing-valves-adjustment-maintenance-and-repair/. Another reason may be a lack of water in your system. In this case, I would recommend checking that in your city or settlement there is enough water for delivering to your house.