Indirect Water Heater? No controller needed?

cwilliams2000

I am looking into getting a SuperStor ssu-80 water heater installed. The local installer is not cheap compared to the cost of the tank, but I am happy to hear how he plans to install it and is adding in some extra items also, like valves to some existing lines.



My concern is that to bring the quote down he has opted to remove the tac controller but told me that he can still install it with a "valve" or relay that will allow prioriity to the hot water and run my exisiting 6 zone valves. But in the future if I wanted to add something else that I would definitely need a controller then.



Can you let me know your thoughts, is this a good thing, bad thing or a mistake? I just dont understand what relay he plans to install?



Thank you

Alan (California Radiant) Forbes

Priority DHW

There's probably more than one way to do it, but the first thing that comes to mind is by using a 3-way zone valve that would direct boiler water to the indirect and away from the heating zones on a call for DHW.



Personally,I would opt for the Taco zone valve or pump controller.  It makes everything easier; enabling priority, wiring and above all, diagnostics.  The lights on the side of the controller tell you exactly what's going on.

bill_105

My favorite-

Is to use a separate circ. with either a Taco SR501 or Honeywell RA889a. Or doing the same thing with a Taco Priority Circ. The latter is just a circ. with a swithching relay strapped on. It also uses less conduits.

But the former allows two replacable parts.

I came across one some time ago where the installer killed the power to the space heating circ. for priority. Thereby keeping the zone valves open and flowing water backwards through the loops. I wired it to kill the 120 volt to the Transformer servicing the zone valves. The homeowners could't believe how quickly the thing recovered.

CMadatMe

Get the Zone Control

Knowing the cost of a zone control and what it takes to install I can't see a signficant cost reduction. Add the zone control and if it is a Taco makes sure the EXP version. You will be able to add out-door reset to the boiler in the future to get yourself some additional savings. Pay today to prepare for tomorrow.

Mark Eatherton

The $100,000.00 relay...

Many moons ago, whilst working for the largest RFH contractor in Colorado, LONG before limited DHW priority was an option, we had a situation arise...



While the HO and his family were down in Florida, enjoying 2 weeks in the Winter sun in the land of eternal fun, his DHW heater called due to system standby loss. It shut off the space heating circulator via the prioritized relay. The DHW pump locked up, as they are prone to doing.



At the time, we were being exposed to a long term Arctic cold front, which froze and broke every potable water pipe in his 10,000 square foot home. When it finally rose above freezing, his home was destroyed by the free running water throughout the home.



I have not done a simple relay DHW priority logic since, and never will again.



Thanks goodness for insurance companies...



ME