As goofy as this is, it works ok

[Rick Stanley]

I was in a hurry, didn't know what I was doing (still don't), threw this thing together just to get some heat on with winter closing in. This summer I want to make improvements. Thought I would start by trying to post what's there (if this Paint program works out), and ask for comments.

The two 15-58's are controlled by the aquastat on the oil boiler set at around 140. The 007's are controlled by the thermostats for each zone. The little circ on the dhw loop is control by a thermostat on the tank. Any thoughts?

Thanks,
Rick

 

[bigburner]

What don't ya like?? How well does it work??

 

[TCaldwell]

Rick, did you post earlier that chris holley wanted to keep the oil boiler hot? it looks like the dwh is piped to the boiler coil. If you piped the dwh as another heat zone, then you could pipe the boilers parallell and tie them in with a injection loop, reducing the oil boiler standby losses when in wood heating mode.

 

[Rick Stanley]

No Tom, he recommended to let it go cold along the same lines as you're suggesting. I have to considered that and other improvements, various ways of accomplishing them, decide if they're worth the trouble and get them done before another year passes. They seem to pass quickly these days

So let's start with connecting the garn and the oil boiler in parallel. I'll pose a question to guys that have done this. How important is it to have the system able to switch to oil automatically?

 

[Nofossil]

No Tom, he recommended to let it go cold along the same lines as you're suggesting. I have to considered that and other improvements, various ways of accomplishing them, decide if they're worth the trouble and get them done before another year passes. They seem to pass quickly these days

So let's start with connecting the garn and the oil boiler in parallel. I'll pose a question to guys that have done this. How important is it to have the system able to switch to oil automatically?

The automatic switching issue is a matter of preference and convenience. Manual switching in some situations has a very low WAF, and we like to fire up the boiler when we leave for a few days - the house will run off the boiler and storage as long as it can, then switch to oil.

 

[bigburner]

Every thing I have switches automatically- some I will manually or electrically hold off [low priority ]

 

[Jim K in PA]

Rick - I did the exact same thing my first season. I kept my EFM oil burner warm all winter to try and keep up with the DHW demand. It did not keep up all the time so the oil burner would kick in to supplement. The oil burner heat exchanger was a huge heat sink, keeping a nice steady draft going in the chimney 24/7. I wasted quite a bit of heat (Wood) up the oil burner chimney that winter. It is more than worthwhile to change things up this summer. I did not have an indirect WH so I had no choice the first season. You have the DHW tank already, so you are just a few steps away from making some big improvements.

My suggestion is similar to others. Put the DHW indirect tank on the primary loop as another zone (secondary circuit). Re-pipe the oil burner as a secondary circuit in the primary. You will have to add a pump to the boiler circuit. Another 15-58 will be plenty.

As to auto switchover, that is really up to you. I have mine set up as a manual switchover (it is not set up as a secondary cicruit - wish it was). I throw two valves to bypass the Garn HX and flip the switch on the burner gun and I can be back to oil. Have not done that since early in the '09 season. It is a simple process and easily explained to others how to do if I am not there, but that is my situation. If you need seemless switchover, it is not too difficult to wire up the relay to energize the GARN circs when the GARN water temp is above the setpoint, and to de-energize the Garn circs and turn on the oil burner and its circ when the GARN water temp is below the setpoint. I am sure Chris can help you plan this out.