installing a new cooktop

[pscot]

Our cooktop died. It's a 20 year old thermador with a downdraft vent. i'd like to replace the cooktop but keep the downdraft system. The 2 systems are separate but the controls for the downdraft are part of the old cooktop. The vent has its own wiring harness but would need a new control panel mounted somewhere adjacent to the new cooktop. I need some ideas about how this might be done, or if it's even possible.

[MADem]

1. You know what I'd do?

I'd buy the thing from a good appliance store, and have THEIR GUY install it!

Then if anything went wrong, they'd be on the hook--at least for awhile.


Wish I could be of more help, but the only thing I can suggest if you want to DIY is to see if they have the same essential model, only newer, from the same manufacturer!

[Old and In the Way]

2. How many wires on the harness coming from the exhaust fan?

I think they would correspond to the number of speeds that the fan has plus a ground wire (green) and maybe a neutral (white). If there are 5 total, then it would be 3 speeds. You might use a rheostat fan switch - tied to the highest speed lead and make it an adjustable (0-max rpm). Is the wire to the switchbox still in place? If so, I'd try to remount the new switch in the same location.

In rereading your OP, I am confused. Is this a downdraft vent or an exhaust fan and is it located on the cook top or over it? My comment above assumes over the cooktop. If it is part of the cooktop I don't see how the old unit will adapt to the new cooktop. If there is a ffan on the new cooktop, it should have it's own set of wires that would connect to the circuit that your old cooktop used.

On edit: I think MADem is giving good advice if you don't feel comfortable doing electrical work....if you proceed, make sure all power if off to the cooktop/fan circuits before doing anything!

[pscot]

4. Exhaust vent that sits across the back

of a 36 inch cooktop. There are 2 connectors, one for the cooktop and one for the vent. Fan is a rheostat, Vent retracts. If I have to change out the vent it will more than double the cost. Maybe it can't be done. OTOH, if I just leave it as is, someone else will be cooking Thanksgiving dinner.

[Old and In the Way]

6. You can clip off the connector and wire directly to the fan power, using wire nuts in the junction b

I assume one wire is power and the other is neutral.

[pscot]

8. it's a pop up vent

so it's a little more complicated. Also it will need a new, separate control panel since the controls are built into the old cooktop. I'm not sure where to go with that. I don't want it to look like a complete kludge. Of course I'm also dealing with three or four mini crises and we're about to be hit by a typhoon. It makes me tired.

[Old and In the Way]

9. It's hard to give advice without seeing the actual application.

In fact, it might not be good advice at all. Hope you make it through the typhoon - sounds like this project is the least of your problems!

[pscot]

10. You might say it's been moved

to the back burner for now.

[TonyPDX]

3. I'll be interested in the replies-- I have a downdraft exhaust & I'm ready to do the same thing.

I have a 20-year old Jeld Wen cooktop and the electronic lighters continue to make an annoying clicking sound, even after the burner is lit. Would love to get this one repaired, but learned that it involves replacing the entire control panel ($$$). I'm worried now that I'll be unable to find a new one that will work with the downdraft. Will keep an eye on your post.

[pscot]

5. The Thermador is a white elephant

A set of replacement knobs cost $20 each. Burner rings can't be had except for generic, which add a slope to the burners. It finally sparked and smoked and quit. My wife talked to a fellow at Lowes who told her to take pictures and show them to some nameless fixit guy who might be able to help us if we can find him. The paradigm is replace not repair.

[Thor_MN]

7. If the lighters have an optical sensor to detect the flame,

They may be coated with soot and just need some cleaning with a Q-Tip.