Hot Water Radiator Heat – Intro

Upon returning from my trip back to the states for Thanksgiving, I entered an expectedly chilly apartment. Before I began the process of emptying my luggage, I turned my radiators up to ‘5’ – the highest setting. I did not presume that the apartment would warm immediately, but as I climbed into bed many hours later, the place still seemed frozen. When I got up four hours later to run my feet under hot water in a feeble attempt to warm up, I considered the fact that something might be wrong.

The Situation

I live on the top floor of a five floor apartment building. We have a shared heating system. And even though the cost of this utility is included in the rent, a “warm rent” is specifically called out in my monthly payments, which acts as a deposit for utilities such as heat and water (as well as other maintenance). I have a hot water gauge, a cold water gauge, and a meter on each of the four radiators in my apartment. I am told that these will be read either annually or at the end of my stay; the actual versus expected will be compared, and the day of reckoning will be upon us.

These four heater meters are centered on the radiators. If the heat does not reach them, i.e., does not trigger usage, one could theoretically get free heat. Unfortunately, I enjoy being comfortable in my home.

The Problem

Each apartment in the building is tied into the same heating system. There are boilers in the basement that heat water and pass it to radiators in the building whose thermostats are demanding higher temperatures. This system will only work if there is enough pressure and if there is no air in the radiators. Well, living on the top floor, all the air in the system has found its way to my radiators.

I spent over a month bleeding the air out of my radiators each day. The one in my living room would take about eight hours to fill back up with water ; at night, the entire system seems to be shut down throughout the building, and this particular radiator fills back up with air again. The radiator in my bedroom would never fully fill; I ended up simply leaving the bleeder valve fully open for weeks on end, hoping one day that the air would fully leave the system.

With the air in the radiators, the water entering the radiator from the top right would warm up the first six inches of the metal before draining back out the bottom right. Note that the bleeder valve is on the opposite end of the contraption (i.e., the left). Some heat would be emitted, but not near enough to warm an entire apartment in a German winter. The most annoying part was lying awake, listening to the water fully drain each evening when the system shut down.

It was during this time that I was baking something almost every day – heating my apartment from the residual heat from the oven after the bread, pizza, or cake was done.

The Solution

After some research, it became clear that the system was grossly under-pressurized. I contacted the property management company a couple days before Christmas. They gave me the name of the heating specialist who would be contacting me in order to show me exactly how these radiators work as well as making sure the pressure was what it needed to be. He never called.

A week and a half later, as I was working through some emails in my living room, a loud whoosh began emitting from my radiators – both bleeder valves were open again for the day. I quickly jumped up and got to the radiator in the room in time to shut the valve as water began spewing out of the valve. I then sprinted to the other end of the apartment where black, brackish water was already shooting out of the bedroom radiator. Someone added water to the system, increasing the pressure and pushed the air out. No one has yet contacted me.

Now, my radiators are set around ‘2.5’ to ‘3’, and it is once again a comfortable temperature in my apartment. The full radiator now emits heat, and I am quite impressed how quickly I can change the temp with a fully-functioning hot-water heating radiator system.