View Full Version : Boilermate/Royall Boiler installation help

10-30-2010, 01:42 PM

We live in a rural part of Alaska and several years ago bought a 2250 sq ft shop type building with the hope of eventually building a home on the property. The 17 year old heating system leaves quite a bit to be desired and consists of a Bock 32 gal heating oil hot water heater (replaced in 2004) that heats all household water and the radiant floor heating. The radiant floor heating consists of two 1000' loops that have a single Grundfos multi-speed pump that pushes the water through. The pump is triggered by the thermostat directly above it. During the winter the heating system works okay provided you have a huge wallet for heating oil, and that the temperature is above freezing. When it gets below freezing it can get chilly, but when it gets below zero, it gets cold. In past years we offset it with a wood stove. We now have a Royall wood/coal indoor boiler that we hope to install. Since the Royall boiler needs a closed system, I picked up a used 40 gal Amtrol Boilermate that was only used for several years, the previous owner upgraded to a larger unit.

My problem is that neither the Amtrol nor Royall installation instructions cover this type of install. With a poorly designed system like this, I'm not sure what is needed and what isn't. As this is hopefully not my long term permanent living space, I'm trying to conserve on what I invest in an already bad design. My goal is to install the wood/coal boiler and Boilermate with bypasses that allow me to turn off the boiler and just run the hot water heater during long absences or the summer. There are no zone valves on the present system.

I thought the boilermate should be installed first as it will be used regardless of what heats it, then to focus on the Royall boiler install.

I've attached diagrams of my present system and the Royall and Boilermate installation diagrams.

Thank you,


11-02-2010, 12:48 PM
Isn't there anyone who can tell me how to lay out my system? If not, can someone point me to an online forum where I can find knowledgable help? It's getting colder up here and I really need to install the Royall Boiler & Boilermate.



11-02-2010, 02:37 PM
Design-by-web forum on this one would be a bad approach.

This is more than a plumbing project, it's hydronic design project. It looks like you're running dual temp (baseboard & radiant) and want to add the Amtrol as a separate zone (which is doable) but breaking into it without a full design overhaul looks like a can of worms. (The method by which the wood boiler and oil boiler are paralleled & controlled is just one of several issues in sore need of attention.) If you can find a competent heating system designer to design the reconfigurations for you, it'll be worth the money in comfort and efficiency (whether you do the plumbing yourself, or hire it out.)

If you can't find a system designer, buy some hydronic design books (http://www.heatinghelp.com/products/Books/5/96/Modern-Hydronic-Heating-Second-Edition-br-by-John-Siegenthaler) for your winter reading, and be prepared to do some math, not just plumbing.

11-02-2010, 03:02 PM
This sort of approach is a bit closer to where you should be going (ignoring the stuff in there you don't have or need), but there are errors here as well (for instance, the placement of the expansion tank relative to the circulation pumps, which is fixable. Pumping toward the boiler & expansion tank pressurizes the boilers with potential over-pressure valve sputtering, and increases cavitation on the pump impellers.)


With wood boilers having a massive buffer tank is useful, since you can then run the burn at best-efficiency without needing to use all that heat instantly.