Greg first:
When the 29" combos were first introduced under both the Kenmore and WP names, they did not have a lint screen on top for the dryer. They had an access panel in one of the perforated sections of the drum and in the intake sump at the bottom of the outer tub, there was a lift out filter that had openings around the edge. The dryer's air stream passed through a centrifugal separator like in Kenmore lint storage dryers, Whirlpool dishwashers with the Power Clean soil separator and the failed WP dryers with the lint storage system that, because it had 100 in the name, made people think that it would store 100 dryer loads' worth of lint. Anyway this particular combo had a tranny that ran the pump and belt for the blower all of the time AND SPUN at 500 rpm. Also in the air stream was a damper that either exhausted most all of the air during dry or allowed only a small part of the air to be vented and most of the heated air to recirculate back into the outer tub. If the machine was in the wash portion of the cycle and the water was not hot enough, the dryer heater came on and blew hot air in to heat the water in an indirect way. The portion of vented air was sufficient to carry off the products of combusion in the gas model. This was on both the TOL gas and electric models. When the dry portion of the cycle started, the damper opened to allow most of the air to blow out of the dryer except for the small amount that was spinning the centrifugal separator and was returned to the machine.
If you remember, the 29 inch combo starts each wash cycle with a one minute purge. Today it flushes lint from the blower. In the original 29" combo, this was how the lint that was caught in the separator was flushed out and sent down the drain. In theory it was almost magic. In real life there is no magic and trouble happened when large amounts of lint from drying linty loads were washed down into the sump and clogged the strainer or when linty loads were washed and this filter for the wash stream got clogged. There was no alternative to lifting the heavy, wet clothes out of the machine, opening the access panel in the drum and removing the strainer to clean the clog. Customers were not happy with this. WP had to come up with the mother of all retro-fittings. They had to replace the top of the machine to accommodate an opening and lid to access the dryer lint screen. They had to redesign the blower housing to hold a dryer lint screen. They had to replace all of the transmissions with a tranny that had a solenoid operated shifter to alternate power between the pump and the blower and with the loss of the constantly powered blower, the water heating was no longer possible. They also had to provide the filter for the water system. All of this was done in the field and the undercounter installations that had been made possible by the original machine had to have the countertop removed. The other great loss in this was the 500rpm spin. It was dropped to 400rpm.
So, no; there was no longer a method of water heating; not the immersion element in the 33" wide electric combos, nor the gas burner sitting next to the U-shaped outer tank of the 33" wide gas models with blower running and damper restricting the airflow during the washes and rinses. The gas burner in the 33" combos had another unfortunate drawback. All of that intense heat right beside the dry tank during the long dry periods, even though the flame did not touch the tank, stressed the porcelain and when it started cracking, water got to the steel and the tanks rusted out.
I had an electric BOL WP 33" combo for a while. It was from the house of a friend who got a lot more help with school work from me than he would have if his mom did not usually have this thing running when I came over. When I got it to my basement and took the panels off, I noticed that where the hose for the bleach/softener dispenser terminated above the water line, there were holes rusted through the porcelain tank. I went to the hardware store, got scraps of glass and bought two part epoxy to patch the holes. The Whirlpool service tech who helped me with my combo had worked for Sears when these big beasts were new. He saw my patches and said it had never entered his mind that the tanks could be patched. When they had to take back these machines because customers were not happy with them, they pounded holes through the outer tanks with ice picks, rendering them useless to people who went through the place where they dumped machines. Imagine-- people going through junked appliances! It would be 11 or 12 years before I was doing that. I guess that it is easier to destroy them when you have had to work on them in tight quarters and had to listen to irate owners and were able to see from the get-go that they had serious design flaws.
