Haven’t posted here in many years...hope I am in correct sub forum.

I want to modify my Bosch washing machine so the hot water and cold water inlet solenoid valves always open together. Both valves share a common 120vac supply. Each has a 1k ohm coil and each is switched on/off with a triac which completes its circuit to neutral. I want to bond the wires leaving each solenoid together so that whenever the control board switches a triac on, both valves will be connected to neutral and open. In the case where only one triac is switched on, I will have twice as much current flowing through the triac compared to the original design...240 milliamperes instead of 120 milliamperes. Without opening up the machine to visually check the triacs, I do not know their rating. I do not know if doubling the current is a totally obvious no problem or must I get to the circuit board and ascertain the triac design rating? Thanks for your help.

 

No problems there , the Triac will be rated at 6Amp or greater, probably a BTA 600-8

 

No problems there , the Triac will be rated at 6Amp or greater, probably a BTA 600-8

Thanks Dodgy. This machine came with the house. It is a massive workhorse but has an unusual selection of cycles which do not suit my wife. To get the right combo of temperature, spin speed and cycle time, I need hot and cold water to enter both hot and cold inlet valves. Modifying the circuit is the “cleanest” way to to the job.

 

Well, bad news. I fried the cold valve triac. Looking at the interconnect schematic, I do not understand how or why this happened. Each valve always has 120 vac going to it’s coil. When the controller calls for cold or hot water, the respective triac completes the respective circuit to neutral. Adding the jumper simply allows both valves to open when either valve triac completes the circuit. It seemed like the cold water was not opening so I removed the jumper. Sure enough, the cold water valve no longer opens. The valve itself is fine and opens when you put 120 vac across it. Next step is to remove the control board, identify and replace the cold water triac.