How do I verify the water heater?
Still waiting for information on how to check the water heater
is it possible to check resistance of the heater relay to verify that it is now burned open. I have no schematic - would need test points.
one gentleman on you tube changes the heater relay only - what do you think of that?
what is the success rate of changing the control board without burning up another heater relay? Have they changed the ampacity rating of the relay?
Where is the most reasonable source for the control board? Amazon has one for $124 seen others for $103 ebay has a refurb for $90
thanks - this unit is 7 years old and I'm just trying to figure out if I should repair or replace. What is your experience with the life expectancy of a Bosch unit?
can you identify which wire to check amperage draw?
How do I get a printout of this discussion?
How do I get a schematic?
water heater replacement seems out of the question
one more question: the fact that it worked at least once after I resoldered it should prove that the problem is indeed in the heater relay again and the only correct repair is a new control board.
Update - after pricing several control units I decided to change just the heater relay. The relay part number is R46-5D12-6 mfg by NTE. It is rated for 12 amps where the original relay was rated for 10 amps. Cost me $10.25 for the part including the shipping. Easy replacement. The dishwasher is now operating like new - much quicker run times.
The relay coil rating/resistance was identical. The amperage rating is what the contacts will take - and I presume since the heaters never fail on a Bosch that it should not be a factor. Unless - Bosch engineers used the relay as a fail-safe to burn out at the 10 amp rating. Seems like poor engineering if that is a fact. The original Bosch relay is no longer available. This is also obviously a common problem since I also changed a relay in a friends Bosch the following day. I would expect that the original relays burned out more due to pitting (arcing) between the internal contacts and not the external load. Anyway - thanks for your advise.