The heating is not hot, I have a small apartment, the first heating door is the bathroom, and then i

Find a property, or find a worker.

You are not specific enough, whether the heater is not strong enough, or your heater duct design is not reasonable, or it is blocked.

Under normal circumstances, there is no problem with collective heating and small apartments.

Let's find a heating company to come and see.

In your case, there should be a series of radiators in your room, in which case if the water pressure is low, the first one will be the hottest, the second will be the second, and the third will be the hottest, until there is no temperature at the end. The best solution to this situation is to add a booster pump to the inlet pipe to increase the pressure of the heating water supply, and then increase the flow rate of the hot water, so that the hot water quickly passes through the first few radiators to the last one. Such an effect should be relatively obvious.

In general, the heating supply of the end radiator will be significantly improved after the booster pump is added. Hope it helps!

Your current plumbing and heating may be connected in series, the first group dissipates too much heat, and the later heating gradually does not have the heat of the previous group, it is recommended that you change the system to parallel so that all the heating will be the same hot.