Ramco St-131 / St-600

[Dr. Spa]

Argggggggggggggggg. My antiquated thermostat died. Hoping there's some other old timers around with some ideas.

Thermostat has two parts, the actual thermostat, which is a Ramco ST-131;

And an interface, a Ramco ST-600.....which died.....and is beyond obsolete (I think mine is 25 years old)

The ST-600 is simply a DPST relay operated by very low voltage (which runs through the ST-131 thermostat), with a built-in transformer. The whole thing just thermostatically controls a 1/20 hp circ pump.

Anyone have any ideas on some kind of replacement?

[Spa_Guru]

You can build your own interface using a 12 V light transformer and a 12 v coil 30 amp relay That t-stat is replacable with an eaton-mears.

http://www.grainger.com/Grainger/OMRON-General-Purpose-Relay-1YCU9?gclid=CPX3g5bi17UCFYZcMgodGXsA7A&cm_mmc=PPC:GooglePLA-_-Electrical-_-Relays-_-1YCU9&ci_src=17588969&ci_sku=1YCU9&ef_id=4ZtPkxE02XIAAEvc:20130228004022:s

http://www.grainger.com/genericZoomMobile.html?asset=Grainger%2F1YCV3_AS01&contentRoot=%2F%2Fimageserver.grainger.com%2Fskins%2F&serverUrl=%2F%2Fimageserver.grainger.com%2Fis%2Fimage%2F&sku=1YCU9&sku_name=Relay%20Flange%20Mount%2C%20SPDT%2C%2012Coil%20Volts&ref_page=idp

[Dr. Spa]

I've replaced the t-stat a few times over the years.

Thought about building my own interface (PITA as it would have to be water tight for outdoor use)...but then found out, the newest upgrade to the Intermatic Multiwave (the controller I use for the rest of the system), has a new feature to handle the heating mode independently of anything else (the old version required it to turn on the pump in order to turn on the heat). Just finished upgrading the software and rewiring. So far it looks like it's going to work perfectly!