Block Heater Install Question

[snowblind]

Hey Everybody.

I put in a block heater yesterday. It's one of the "circulation tank" types and I bought it at Napa for around $60. Here's a link.

The instructions told me to tap the heated coolant hose into the upper heater hose that connects the heater to the water pump. I did and everything is working but because I tapped the top hose the rest of the heater is staying cold.

So... can I tap into the lower heater hose instead? This hose connects the intake manifold and heater. I believe this is the "normal" route that the coolant takes -> Manifold -> lower heater hose -> up through the heater core - > down the upper hose to the water pump.

Any problems with connecting to the lower hose that y'all can think of?

Thanks.
Matt

[Mercury694]

It's got a thermostat, so I don't see any reason to worry about any significant problems. I'd think the main issue is making sure you keep the warm water on the engine side of the thermostat while trying to get as much of the block running warmed water as possible. If you take water from the water pump (lower radiator hose) you should be running it through the return line from the heater core to get the most exposure for the block. If you're looking to make sure your feet are warm first thing, you could route it through the heater core circuit as a whole, with the understanding that you are sacrificing some of the heat. I don't see any technical issue, the question is whether or not the water heater can keep up with the load. I suspect it will be fine unless it was marginal to begin with. Make sure your temp slider is always all the way over on "Hot" when the block heater is plugged in so you don't deadhead the block heater.

[snowblind]

Hello Savannah! I lived there for 5 years in another life...

The heater is low on the frame coming off the block coolant drain not the bottom rad hose. It is the lowest point in the cooling system.

I'm pretty sure that the only way for the heated coolant to exit the block is via the thermosat. With the current mild weather my heater actually gets the engine hot enough to open the thermostat but as the temps drop that won't happen. All the hoses except the lower rad hose get hot but the lower heater hose gets cold as it nears the heater box

Looking at the way the system is laid out I think it will work fine. The hot coolant should rise through the heater core and then flow back down to the water pump as it cools. It's exactly the path that the stock coolant takes.

EDIT: Thinking about it a little more and I can see maybe how the heated coolant still has an option not go up the heater core even if it was attached at the bottom. and instead try to creep up the heater hose that comes from the manifold. This would essentially bypass the heater and also the water pump. I think I'll try the lower hose anyways and see how it goes. If it doesn't work it isn too hard to set back the other way.



Matt

Originally Posted by Mercury694

It's got a thermostat, so I don't see any reason to worry about any significant problems. I'd think the main issue is making sure you keep the warm water on the engine side of the thermostat while trying to get as much of the block running warmed water as possible. If you take water from the water pump (lower radiator hose) you should be running it through the return line from the heater core to get the most exposure for the block. If you're looking to make sure your feet are warm first thing, you could route it through the heater core circuit as a whole, with the understanding that you are sacrificing some of the heat. I don't see any technical issue, the question is whether or not the water heater can keep up with the load. I suspect it will be fine unless it was marginal to begin with. Make sure your temp slider is always all the way over on "Hot" when the block heater is plugged in so you don't deadhead the block heater.