Home » Transfer Switches » Single Circuit Generator Transfer Switch, For Furnaces, Boilers & Sump Pumps

Single Circuit Generator Transfer Switch, For Furnaces, Boilers & Sump Pumps

HTS15-MANThought I would share the news of my new single circuit transfer switches that I make through my company Heezy LLC. Pictured is the newest Manual transfer switch and I also have an automatic version.

They are quite easy to install even if you don’t have much experience with doing electrical work, I include easy to follow instructions and even have a few videos on installing them.

If you would like to read more or order one, please check out the HTS15-MAN manual version here, or the HTS15-AUTO automatic version here.

Thanks for all those who have ordered, asked questions or given me some advice along the way.


  1. Todd says:

    I recently wired a DIY transfer switch for my gas furnace to run off a cord to a gennie or inverter. Now I’m wondering if it’s the right thing.

    Only cost about $30 for a 4″ metal work box & cover, a length of cord and 3-prong plug, wire nuts, connectors, etc., and the main part: a 20A DPDT toggle switch, (On-Off-On). Mounted the box right to the side of the furnace where the wiring enters. Put the flex conduit into the side of the work box. Nice clean installation.

    Question: is the DPDT toggle adequate for a transfer switch? When it’s thrown to “aux power” (i.e. the cord), there is no longer any connection back to the main breaker panel, (except perhaps the ground).

    Is this safe/legal/kosher/ to code, or do I need to buy a UL-listed transfer switch like you show?

    I like yours with the breaker and light, but I’ve already installed this one. Tested and it works great, but I haven’t run it from the inverter…. Will a square wave inverter run my furnace, or ruin the circuit board? I’m a little afraid to try it.


    1. Rick says:

      Hey Todd, Yea sounds like you’ve done it right. If the DPDT (on-off-on) switch is rated for 15 or more amps your good there. All the Transfer switches made use a DPDT switch with a Center Off Position thus allowing no chance of cross or back-feeding the power. you won’t have any issues with the inverter ruining your baord, I’ve done several post on this, more can be read here; If the inverter won’t run it the first time, try grounding the inverter to your main house ground or adding a new one, if that doesn’t work try a ground-neutral bond. Cheers

      1. Todd says:

        Thanks Rick for the advice. I really enjoy your web site, good stuff here. Found it from the forum on TSP.

Leave a Reply to Rick Cancel reply

Your email address will not be published. Required fields are marked *


About Rick

I've been an HVAC/R Mechanic working in the Seattle area for over 15 years, specializing in the commercial service industry.. I’m also a Licensed Electrician & Gas Piping Mechanic and have numerous other trade related certifications. I’ve instructed at local trade schools and now continue teaching through this site.

Get on the list!

Sign up for updates from me, I hate spam probably more than you! I will never sell or share your info.
* = required field

powered by MailChimp!
You might also likeclose
- Privacy Policy