Replacing DVS Controller

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#324166 8-Mar-2026 19:36

My 20+ year old DVS still works but the control panel lights are all flashing.

Looking at the unit, it's just a 240v fan plugged into a control box which has a standard three prong plug with two cables coming out 1) cable for the control panel which is downstairs and in the house and 2) thermostat cable.

I've replaced the thermostat cable with a similar one from aliexpress but still the same problem.

Other options are:

a) plug the fan directly into the power

b) plug the fan into a timer or wifi control box so I can manually turn the fan on and off

Ideally I'd like to replace the controller with someone cheap from Aliexpress. Lots of options but not sure what will work.

Any thoughts/suggestions?

timmmay

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#3467948 8-Mar-2026 19:47

I ripped out some old system and its buttons and display in the house, now it's just a fan plugged into a WiFi timer plugged into the mains. I don't know anything about your system but the general idea is sound. What does the controller do?

tweake

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#3467958 8-Mar-2026 20:44

you would have to see what sort of fan motor it has and the type of controller. a lot of older ventilation systems use a standard 3 speed fan and the controller has relays to switch between the speeds. so you could at least just configure it to one speed.

personally i would just replace it with with the modern ecm fans and controllers.

larknz

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#3467961 8-Mar-2026 20:52

Just remember that a controller purchased from Aliexpress is unlikely to have an SDOC, so won't be compliant here. If something goes wrong your insurance will probably not cover you.

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#3467963 8-Mar-2026 21:06

timmmay:

I ripped out some old system and its buttons and display in the house, now it's just a fan plugged into a WiFi timer plugged into the mains. I don't know anything about your system but the general idea is sound. What does the controller do?

Controller basic turns the fan on and off depending on the temp in the ceiling. In the summer you don't want it blowing hot rooftop air back down into the house.

To be fair I've had it off all summer and didn't notice any difference - it's really the winter when I need it to stop condensation on the windows.

timmmay

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#3467966 8-Mar-2026 21:16

Sounds like a Wi-Fi timer would be fine.

tweake

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#3468178 9-Mar-2026 19:32

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Controller basic turns the fan on and off depending on the temp in the ceiling. In the summer you don't want it blowing hot rooftop air back down into the house.

To be fair I've had it off all summer and didn't notice any difference - it's really the winter when I need it to stop condensation on the windows.

trouble is thats not really true. its a ventilation system, not a condensation removal system (they often use a dirty trick to do that) or a heating/cooling system.

every home needs ventilation, preferably constantly. you might not notice a difference, but you certainly can measure the difference.

sucking in hot ceiling air can be fixed by using a "summer kit". its just a duct and outdoor grill, with a damper so you can select ceiling air or outdoor air. use an electric damper Y fitting and a basic thermostat, and you have an automatic summer kit. really easy to make. then you can ventilate year round.

typically the systems slow down in really hot/cold temps and then compensate by going faster than required in more mild temps. but if you have decent heating/cooling its not a big deal (except extreme climates) to just a have constant air flow.

for eg most systems get installed so that it blows air in behind the curtains and down the window. that is what stops the condensation in winter, but it also removes a lot of the insulation qualities of your curtains. so you have to heat your home more, and i'm guessing you didn't notice the difference. yes they pull a dirty trick on ya.

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MikeAqua

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#3468322 10-Mar-2026 09:32

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Ideally I'd like to replace the controller with someone cheap from Aliexpress. Lots of options but not sure what will work.

Any thoughts/suggestions?

(emphasis added)

AliExpress is selling people now? I guess it was the next logical step.

Mike