Go figure

Even though I am a university professor, subject to many of the failings of my profession, I have always prided myself on a certain level of practicality. Unlike some of my academic colleagues, I paint walls and drill holes. I have been known to build small pieces of furniture which do not wobble. I can do simple plumbing and electrical stuff, and am sometimes able to determine why a vacuum cleaner or a coffee maker no longer works. Experience and considerable success in these matters have induced me, in normal circumstances, to attempt to figure things out for myself before calling in a professional, and this has almost always paid off, not only financially, but in the satisfaction one draws from a job well done and from the cluckings of envy one occasionally hears from the wives of less gifted colleagues. A few years ago, when I took a sabbatical leave in France, I was confident that these abilities would be directly transferable from Calgary to Paris.

On my arrival in Paris, after overcoming the usual administrative and practical difficulties, I finally managed to rent a small apartment in the 1er arrondissement. It was situated just under the roof on a sixth floor and accessed via a narrow winding staircase with a cast iron railing and well-worn wooden steps which the concierge, not a small woman, carefully polished on her knees every week. I remember the first night in the place was very cold. It must have been October or early November and Paris can be freezing at that time of year. The apartment had a modern heating system, much vaunted by the proprietress, a perky, petite young woman who had been living there alone until her recent mariage to an up-and-coming plumber from the suburbs. It consisted of two electric radiators on little wheels which you plugged into wall receptacles, so connecting them not only to the electricity supply but also to a thermostat mounted on the kitchen wall. Unfortunately, the thermostat had been wired in such a way that when the room reached the temperature you set on the dial, it turned the heating on, instead of off. At first, of course, I didn't realize this. The room was cold, and it seemed that whatever temperature I selected, the thermostat would not turn the heat on. I imagined that the thermostat might be broken, but fortunately this was not the case. For the thermostat to turn the heat on, the room had to be warm, or the thermostat had to believe it was warm.

One way to achieve this, which I discovered later, quite by accident, was to turn the thermostat down to whatever temperature the room happened to be at. The thermostat then turned on the heat and later when it was warm you could reset the dial to give you the impression that the temperature was being maintained at a constant level. Of course, this was not really so. Once it turned the heat on, the thermostat would not turn it off unless the room cooled to below the temperature at which it was set. And the only way to get this to happen, short of a power cut, was either to unplug the radiators, or to open all the windows on a sufficiently cold day, and wheel the radiators as far as possible away from the thermostat.

Now there was another way to get the thermostat to turn the heat on, though it was not immediately apparent, and that was to make constant use of the refrigerator. The inside of the refrigerator, which was maintained at a low temperature by its own internal thermostat, would then warm up, because slightly warmer air from the room would enter each time the door was opened. When this happened, the fridge's thermostat, which worked perfectly, would turn on the fridge's cooling system, situated at the back of the unit and directly underneath the room thermostat. As the inside of the refrigerator was cooled, heat escaped from the cooling unit to the outside and rose to the level of the room thermostat, inducing it to believe that the room was warm, and therefore to turn on the heat. The physical properties of heat, which always tries to rise, and of cooling systems, which give off heat in one direction and cold in the other, were reasonably well known to me all along, but the way in which they worked together in the flat to get the thermostat to turn on the heat did not become clear to me for some time, so keeping warm was a matter of luck, blankets and patience for several days.

In order to keep the above description simple, I have purposely omitted mentioning the water heater control unit, also situated on the kitchen wall underneath the room thermostat, and which, due to some internal malfunction of a kind which I believe is common in electrical switchwork, heated up when in use and also affected the thermostat. Whether it affected it more than did the refrigerator cooling system, so that instead of opening and closing the fridge door, I would have been better employed running hot water for baths, or less, as I first assumed to be more probable, I cannot say for sure. In any case, the role of the water heater control unit did not become apparent to me until after I had repaired the room thermostat, so a choice was not really open to me at the time.

When I finally realized that the reason for my problems was that the thermostat turned the heat on instead of off when the desired temperature was reached I at once borrowed a small screwdriver from the concierge and reversed the two wires which connected the thermostat to the rest of the circuit. This operation was really very simple and I was helped by the diagram clearly printed on the inside of the thermostat cover, with instructions in English, which the installer had obviously not noticed, understood, or seen fit to follow. Apart from a small spark which flickered across the two contacts when they closed, or opened, the thermostat now worked perfectly. When I set the dial, the radiators turned themselves on, and they clicked off when the room was comfortably warm. I returned the screwdriver to the concierge and lived for a while in smug satisfaction.

I was taking a shower, just a few weeks later, when the water suddenly ran cold. This was unpleasant of course, but also unusual, because the hot water tank was large - it took up most of the space above the bathtub where you might have wanted to stand up when showering - and it worked automatically. Like the fridge, it had its own internal thermostat, which switched on the heating element whenever the water fell below a certain temperature. This it was obviously no longer doing. Over the next few weeks, I discovered that it hadn't actually stopped working, but that it now worked intermittently. Since it had worked well before I repaired the thermostat, and since it was now clear to me that the different parts of the electrical system were highly interdependent, I at once suspected that my repair might be the cause of the trouble, and that when the room thermostat worked properly, it might be impossible for the water heater to function, although I could not imagine why.

It was at this point that I discovered, upon careful inspection of the whole circuit, that the water heater control unit heated up when the water heater was in operation and combined with the heat from the refrigerator cooling unit to affect the room thermostat situated above it, as I have already explained. However, the effect now was the opposite of before. With the thermostat working properly, the heat rising from the cooling unit and the water heater control unit together caused the thermostat to switch off the radiator before the rest of the room reached the desired temperature. Instead of working for me, these units were now working against me, though I had not been noticing this because by the time I had understood the fault in the thermostat wiring and corrected it, spring had arrived and it was much warmer.

So the problem now was not so much the heating of the room as the heating of the water, and it was still not at all clear to me why the water heater no longer worked properly. The fault was all the more difficult to detect because the heating element was quite inaccessible and had no tell-tale light or noise which would have allowed me to see or hear whether it was working or not at a particular time. A sudden cold spell provided the solution. During the cold weather, the water heater worked very well. As soon as it became warm again, it stopped. At first this obvious connection with the weather caused me to abandon my original hypothesis, which was that my repair to the thermostat had caused all the trouble. It was not my reversing the polarity of the thermostat wires that had caused the water heater to stop working, I now thought, but the warm weather. This new hypothesis got me nowhere. I racked my brains, but could not imagine how a water heater, which is simply a heating element in a tank of water, might be affected by the arrival of spring.

At last, it was a combination of the two hypotheses which gave me what I now believe may be the correct solution. The water heater worked well when it was cold because that was when the room thermostat turned the heat on. There was some complicated wiring relationship between the water heater and the room thermostat such that when the room thermostat decided to turn the heat off, the water heater was turned off too. Since, as I have explained, when the water heater began to work, its control unit heated up and induced the thermostat to turn the heating off (originally on, of course, so the heater worked fine then, but now, since my repair, off), it couldn't work for any length of time, and neither, now, did the heating. Only when it was very cold were they both switched on frequently enough for the water to heat up and the room get warm. In the summer, I would not be able to have hot water at all.

It turned out to be impossible for me to redo the wiring of the water heater, much of which was hidden behind plasterwork. Of course, I considered calling in a professional, but it was late in my sabbatical by now and in any case I knew it was hopeless to attempt to explain to an impatient Parisian worker not only the various electrical interdependencies but the role of the weather. The French half close their eyes and can be very cutting when they judge your explanations inadequate. In the end I just switched the wires on the room thermostat back to where they were when I arrived, unplugged the radiators and set the temperature on the thermostat to zero. The water heater now worked perfectly all the time, which was all I needed for the summer. In September, I returned to Canada, leaving the apartment to a brash American youth with a hauntingly pretty French girlfriend. After looking around the place, while she sat fetchingly on the little bed, he explained to me with wide, powerful gestures how easy it would be to improve it, recaulking the windows, adjusting their catches so they wouldn't fly open at night, fixing the wall plugs so they all worked, and stopping the drip in the toilet. The pretty girlfriend seemed impressed, so I chivalrously refrained from mentioning any problems the young man might have missed, and wished them a very pleasant stay.