turning heater off

[rjbaren]

I think he means plastic over the air intake in the front trunk

[dakazman]

  Aughh that’s right, I completely forgot about that intake.
  It’s probably the easiest but the heat is still in the cabin area.
Dakazman

[andyj007]

ok so i need to get the manule out to understand the system, .
firstly clearly my heater rad i still getting hot, so my valve is sticky or broken.  i have two of the clamps posted earlier comming tommorow to try..
i have an lots of heat comming through the front vents directectly under the screen..  when stationary this is pretty much non flowing, but when traveling this blows in fast..  guess it is fed through natural air passage.  is that the center hole in the bonnet?  that was suggested to be tapped closed..
regardless if my heater rad has hot water or not im guess8ng  there is no way of shutting air of to this feed,
the vents under the dash open and close letting heat from the heater rad or just cool air if the heater has its hot water feed closed properly..

have i got that right?

[SilverBeast]

You are correct in all you said.
The control in the front of the armrest just controls the heat of the heater radiator.
Speed related airflow will always travel into the heater radiator through the hole in the centre of the front luggage compartment/plenum chamber.  This will always blow into the screen at whatever is set by the heater control.
The flaps on either side of the heater determine if air also flows out onto the passengers legs.
Air flow can be boosted using the heater fan, which is actually mounted on the outside front of the front luggage compartment/plenum chamber in the compartment where the spare wheel is stored.
The eyeball vents at either end of the dash only deliver ambient air, again speed related flow rate, with the same fan boosting flow as the air to these is also delivered via the two holes at either side of the front luggage compartment.  These can be closed individually.

If you fill your front compartment,  you won't get any airflow!

[andyj007]

great thanks for the confirmation..  will tape that off, crimp the hoses..   and see how e get on..

[GavinT]

Andy,
The other thing you could do if you just want to shut the heater off permanently is to use short lengths of hose on the water pump connections and clamp a bolt in those short hoses.

This would leave all the cold air flow to be directed as you wish.

[dakazman]

  I agree with Gavin .
   Another way would be to take the hose off the pump. Buy a 5/8 heater hose approximately 18” long and connect the supply and return line .  This will give you time to flush the lines and the valve and still drive the car.
Dakazman

[jbcollier]

If you just join the supply and return heater connections, bypassing the heater core, then you have a lot of coolant bypassing the radiator.  This may lead to overheating on a hot day.

[dakazman]

    It seems to me that the flow would be shut off at the valve anyway unless there is a leak rate in the off position built into the valve gate.
  So your saying hot water is always running into the box and the air vent doors should be shut.

   I’m only questioning this because I don’t have a heater and I do plan on bypassing in this manner.
  I will surely watch the water temp gauge.
Dakazman

[jbcollier]

If you also plumb in the shut off valve, then it won't be a full-on bypass.  If you are not hooking up the heater core, then just don't hook anything up and fit plugs to the inlet and outlet.

[BobW]

It's an interesting discussion. My S2 has never had a problem shutting off the heater valve completely from the control on the console. It must be one of those situations where your experience may vary!

[dicksanderson]

 The heater control knob on the console is hard to 'maneuver'.  Regardless, I am not getting HOT AIR into the cabin through the 2 vents by the windshield.  I don't have the owner's manual, so can one of you provide instructions as to which POSITION of the heater control know will turn the heat off.

I have a '74 Twin Cam Special.  Thanks much for responding! 

[SilverBeast]

With the heat control knob in the armrest pushed in (towards the back of the car) the valve screwed into the thermostat housing should be fully closed, for cold air. If it's still getting warm your valve isn't working.

[jbcollier]

All the manuals can be found here:

http://www.lotus-europa.com/manuals/index.htm

The heater valve used on the TC is well known for being problematic.  Often you can have it set to close properly or open fully, but not both.  Very common for people to disconnect the control cable and work it manually.  Check and see if yours is disconnected.  New valves do work better than 50 year old ones.

[SilverBeast]

And by the way