I installed a small after market heater inside the cab of the truck figuring it would be more efficient heating semi warm air than cold outside air. But I don't want to cook in the summer. Would one shut off valve on the supply to the heater do the trick or will it back feed heat to the core from the return line? My heater hose runs from the Big Block Chevy intake manifold to the heater and returns to the pump. Another short byp*** hose runs from manifold to pump.
The heater core needs flow through it to heat up so one valve any were in the loop will prevent it from heating up. My after market heater came with a valve similar to this. https://www.amazon.ca/Four-Seasons-74828-Heater-Valve/dp/B001B7BUAU Phil
Use a pex ball valve sold at all the lumber supply places, they work great and will not corrode and not expensive. That's what I used on my 48.
As stated above, either side will work as long as the flow is blocked. That said, the supply side would be the best choice, the return side will have a "pull" on it from the water pump.
Beat me to it! Br*** body, stainless steel valve. Compact and only a 1/4 turn! They are also available with PEX ****** on one end and pipe thread on the other. Would work directly to the head or manifold port. Fewer clamps, potential leaks.
I re-plumbed my heater hoses using 1/2" copper tubing in order to exit below the firewall. For a shut off, I used a gas line ball valve, wrapped with Dynamat, to insulate from the heat.
I put a ball valve from Napa on an off topic one ton Ford truck. I did it so the A/C would get as cold as possible since the coolant never completely stopped circulating through the heater core with the original design. It worked great except when a rain storm would roll through and I needed some heat for the defroster to work. I eventually found a vacuum operated valve and T-ed it into the max AC function so it would close without having to open the hood.
Yeah, I have a valve that I was planning to put on the supply side which of course would stop circulation BUT without valve on the return side, which seems common, there would still be standing hot water in the hose and heater core since there's no valve isolating the core from the pump. It seems to me that some heat would migrate through the standing water in the return line. For those with a valve on the supply side do you find the heater core warm to the touch when the valve is shut during the summer? I could easily put a second valve in but see a single so often that I was curious.
The amount of heat "migrating" to the heater core would be negligible. Shut off the hottest side, which would be the hose from the intake. Also, the valve you showed is typically used as a temperature control valve, so that you can regulate the amount of heated coolant that flows through the heater via a cable connected to the control arm on the valve. If you want to shut it off completely a ball valve will be a lot cheaper.
I would get a valve that you can control from inside the cab with a control cable. It is no fun being stuck out in the rain or snow if you have to prop up the hood so that you can see out the windshield.
I got one for some sort of Ford product that went on the heater hose and had a valve to shut the water off with a hole for a cable to run inside the car. funny, but the car never ran quite the same after that. I never fully realized how just a little bit of Ford can ruin a whole car.
Ford heater valve that goes in the hose Ebay item number simply because I have had it on my watch list but you can buy one locally crossing the oem part number. Easy to hook a cable to or if you are cheap easy to adjust by hand . eBay item number: 310234390594 I've had it on my watch list for several years because it doesn't get much simpler than that.
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