I have heated my house with my EKO 40 for the last two winters with no problems. I have 500 gallons pressurized storage in my basement and the EKO is in a outbuilding 150' from the house. I have 1 1/4 thermopex underground to the house. I built a 30x50 stick built shop last summer and just finished installing air conditioning. I used a Goodman air handler and heat pump condenser in the shop. I have 1" thermopex from the EKO to the shop which is 100' away. The lines going to the shop are T'd into the supply line and return lines near the boiler. I plan to use a water/air heat exchanger in the shop duct work. I will use a small three speed taco pump with integral flow check for the shop loop. My question is will I get flow through the shop loop with the main boiler pump running and the shop pump off? I don't want gost flows through that loop when I'm heating the house only. I'm not sure if the integral flow check will stop this flow or if I need a zone valve. The shop is about 5' higher than the boiler shack. Attached is a picture of inside of shop and new air handler.
![Finally bringing heat to the shop - questions Finally bringing heat to the shop - questions](https://www.hearth.com/talk/data/attachments/136/136188-003bdd250b94011477a44a5e2bc5f981.jpg)
![Finally bringing heat to the shop - questions Finally bringing heat to the shop - questions](https://www.hearth.com/talk/data/attachments/136/136188-003bdd250b94011477a44a5e2bc5f981.jpg)