Dishwasher control system query

[Newshound]

My Bosch has two pumps, two dispensers, a water inlet solenoid valve, another solenoid valve (perhaps for resin regeneration?), and a heater. That's seven "mains" devices to be switched.

The board has three triacs and four relays, so the numbers add up. But why not all triacs? Perhaps the heater and the motor start currents are beyond the rating of the tiny surface mount triacs?

I've had no success at all in locating a technical manual, in spite of lots of potential leads. A marked contrast (for example) to combi boilers where manuals seem to be readily available.

TIA

[Steve Walker]

The timing of the operation of the triacs may be being used to adjust the pump speeds and the heater output for different programs, whereas the solenoids are just open or closed and relay is ok for that.

That's just my thoughts though.

SteveW

[Newshound]

Good point, I hadn't thought of that

[Graham.]

I had to look up "resin regeneration" because I hadn't heard the term before. I wonder how many of these machines with the additional sophistication and expense get installed in soft water areas?

[Steve Walker]

I think that all dishwashers have the water softening resin and a system to regenerate it using salt. For those of us in soft water areas, we just don't use salt - although many dishwasher tablets are now tailored to regenerate the resin.

Personally I am always amused by the numerous adverts for Calgon limescale remover that are shown in soft water areas.

SteveW

[dennis]

That is untrue, in fact its a lie the "salt action" marketers made up. It can't regenerate the resin as only the clean tap water + salt goes over the resin, not the dirty water with the tablet in.

Dishwashers don't scale up in hard water areas either as they have a water softener.

[Andrew Gabriel]

The tablets don't regenerate the resin, they soften the water after it's gone into the wash chamber. They work out much more expensive than using standard powder or liquid detergents and keeping the salt and rinse aid topped up, and with tablets, you can't dose according to expected washing requirement so it's max dose every time regardless of requirements.

[NT]

es:

Really? Where do you get powder that works out cheaper?

NT

[Bob Eager]

CPC.

[NT]

e:

I cuoldnt find delivery price or rinse aid on there. I expect with those added it works out more expensive than basic tablets.

NT

[Bob Eager]

When I worked it out, it came out about half.

You asked about powder, not rinse aid...if you bought enough, delivery would be free. Delivery is free over £45, but I assume most people on here use CPC for other stuff. As for rinse aid and salt, I get them at Costco (look out for me tomorrow afternoon in the Thurrock one!)

[Bob Eager]

To save a wasted journey (!) I should correct that...I'm going on Monday!