Alex, The pressure chamber has been the cause twice for a similar problem as described here: http://ths.gardenweb.com/forums/load/appl/msg0413510827197.html Although the symptoms are much the same, there are differences not present this time: - the special sound stemming from the lack of water in the sump - the ability to help the dishwasher finishing the cycle by throwing 2-3 litres of water into it Also, it does actually finish the cycle after 7-8 hours. I am pretty sure the pressure chamber or heat exchanger isn't the cause this time. But I could check if you think it could be the cause even though the symptoms are different. But what about the power consumption of the heater. At 900 mA at 230 V it consumes only around 100W. Even if the pressure chamber or heat exchanger was clogged, it would consume the same power, wouldn't it? I guest there is only a on/off function of the heater. If not the heater itself, I am wondering if there could be a bad connection somewhere etc. By all means correct me if I am wrong in my assumptions about how it works!

I had a similar problem and it's cause was never exacltly figured out, but it was causing an even bigger problem. I had carbom dioxide in my home. My kids were getting headaches at the same time my husband was. It might have been going on for years before I got a carbon monoxide detector. I had all kinds of experts in to help figure it out. Here's what we figured out that triggered it. When the heat was on on one level and airconditioning on the other. Of course we didn't do that on purpose but there are times of the year when you go back and forth between them. Also if it was really cold and we had the heat on downstars and had it off upstairs. That would make the heater work to hard and it couldn't get enough oxigen. They also thought that if I left the flue for the firplace open, that could cause a problem.

I noticed HU-115683754 also got a new Pentair VS pool pump. I have just installed one, cleaned the filter(2X) by the way. Clean the skimmer baskets and the pump basket, turn pump on, wait for it to totally fill filter, removed the air from the filter, and wait 2-3 mins to turn on heater. Heater runs for over an hour, then goes into 'LO' mode and Service light comes on. If I stop heater, stop pool pump, remove the pump basket and totally clean it and start everything, heater runs for about an hour. The pump basket is not full but the outlet part of the basket gets clogged with debris and it looks as the GPM drops also but not below what filter and heater require to run. Could it be it is this pump basket is just getting clogged? Also installed a flow meter which averages around 50GPM/4.9 velocity leaving the pump.

Splurge Coffee - like French Roast but buy Costco Kirkland which is a good deal. Beer - DH likes small breweries beer or imported. It is one of his few expenses and he works hard so deserves it. Food - Occasionaly we will buy something special like the expensive creamy blue cheese or lobster. But only a couple of times a year. Egyptian cotton sheets/towels - After 32 years of cheap towels and sheets I finally broke down and got some nice ones. My old skin appreciates it. Kitchen Appliances - Finally remodeled our 1971 kitchen and since we DIY, we splurged on the appliances but nothing else. Hobbies - DH occasionally has to buy new tools for the remodeling projects. I buy tools and materials for my metal and glass art projects. Dog - Elvira get special diet food, she needs and deserves it. Anything she needs medically she gets and once a year teeth cleaning (so expensive!). More expensive TP - My old B*t can't take the scratchy stuff anymore. Don't Clothes - I buy a lot of them at Ross and other discount places as well the thrift store. Shoes - Buy them at Payless or Kmart. I hate shoe shopping! Purses - Buy them at the thrift store. Books & DVDs - check them out at the library. Dinners out - we only go out on special occasions. DH says I cook better healthier meals at home. Wine - $2 Chuck is fine with us. Latest electronics - I wouldn't have any of it if we didn't need to but DH does need a cell phone for work, got the cheapest prepaid we could fine. Basic Satellite - We are in a rural area in the mountains so we get nothing without it and keeps DS happy, but again got the basic package. Manicures & Pedicures - I finally got a manicure at 56 YO and wasn't impressed so never again. Haircuts - Go to the cheap chain places. I had my haircut by a stylist 28 years ago and I am still in sticker shock. Hair color - out of a box when on sale. Furniture - All bought used or unfinished (32 years ago) and refinished. Vacations - Haven't had one in over 8 years. DH uses the time off to work on the place and do remodeling projects. (Should remodeling go under the Splurge category?) Cars - We buy the less expensive ones that have been returned to the dealer after a short period. You save a bundle that way. And keep them 11 to 13 years. House - Bought a small place on 2.5 acres that needed a lot of work and have been doing that for 22 years. We could have got a mega mansion and really gone into debt forever but don't need the space. Veggies & fruit - I have a big garden and fruit trees. I can, freeze and dry a lot of what I grow plus have a garden all year long with the basics like lettuce and carrots, etc. Hired Help - Never use any, do all the work ourselves. Have only hired someone when it required big or specialized equipment. We dug out our septic tank, cut down 80Ft trees, ran our own trench lines for watering. You get the picture.