Click here to Find a Contractor in your area.
Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit

Solar Control

Mike Dunn
Mike Dunn Member Posts: 189
A very basic digital differential controller

Eagle 2 is under $200.00


  • Plumber5209
    Plumber5209 Member Posts: 4
    Solar Control

    I have a customer with a 1980s solar hot water heating system. The control that runs the circulator is no good and I am having trouble finding a replacemant. It is a Robert Shaw Solar Comander. I called Robert Shaw and the only person that new anything about it said it was only a prodotype and he never new that they sold it. All I need the control to do is when the tank calls for heat to also read the temp on the pannel to see if there is any avalible and either run or not run the circulator. Any ideas would be helpfull thank you Derek
  • Tekmar....

    Differential controler. model 155.

  • Andrew Hagen_2
    Andrew Hagen_2 Member Posts: 236

    Caleffi iSolar1 Control

    As far as I know, the Goldline control is no longer available?
  • SPB
    SPB Member Posts: 14

    I've used both the Tekmar as well as the Gold line and there are some others also. I stumbled on to a Honeywell T775.. The relays are self powered so you don't have to have a transormer plus it was less than $200.00. It was kind of a do all control, (they have different models and maybe a good control sales person can help match exactly.)
  • Metro Man
    Metro Man Member Posts: 220

    Depends what type of system you have. You now have the opportunity to install something that is tailored to they're system. Is it a glycol, drain-back, drain-down or ????

    There are a plethora of controls on the market now and some that are the old reliables and have stood the test of time. Expect to pay more for digital.

    I would stay away from controls that do not have a proven track record.

    That said... Steca, Goldline, Resol, etc... are all good. Tekmar seems to be the most accurate but they need 24 vac to power up. Wish they would come out with a 110 vac replacement that is cost competitive......

    Metro Man
  • michael_34
    michael_34 Member Posts: 303
    Solar controller

    Been using Resol Delta Sol BS plus
    Really easy to use and great display
  • hot_rod
    hot_rod Member Posts: 15,066
    Caleffi i-Solar

    have some features that are unique to them that Resol has provided. The V-bus connection for data logging is standard and two models offer variable speed pump control.

    Caleffi i-SolarSolar 3 and Solar Plus have two relays which can be used for managing other loads.

    Here is an example of a system that could use two differential controls very well. One to run the solar input, the second to control a 3 way zone valve to shuffle the load from solar to back up. Both functions could be handled, managed and data logged from one control.

    I thought Goldline was bought out several years ago and the new company discontinued production? Has that changed? Or are those old inventory Goldline controls?

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Metro Man
    Metro Man Member Posts: 220

    Nope.... Goldline is still at it. They are owned by Hayward but are still making they're controls. Probably one of the most bombproof, easiest to wire controller out there.

    Also one of the easiest for a homeowner to understand.

    Wish they came with a digital option though.

    Metro Man
This discussion has been closed.