2000 tc Heater Blower no hot air

So it looks like you do not have coolant flow through the heater. Perhaps look at post #18 and try that. You need both flow and return to the heater to be hot.
I had a cold heater on my Lotus, pipes were cold. Turned out the stub for the flow hose on the cyl head was blocked. When I took the hose off it was solid, I ran a drill bit into it and it has stayed fine since. It takes a bit of detective work to figure out where the blockage is if you have cold hoses.
You could take off the rad cap. One at a time disconnect the hoses at the heater and blow hard down each, the coolant should bubble at the rad cap neck. This will tell you each hose is clear back to the rad. If so then flushing the matrix is next.
You may find after post #18 it works and it was just low coolant level. I had a cool heater the other week, I did the post #18 trick and hey presto hot air again.
 
Last edited:
Right, Tried getting the front of the car higher by putting the front end up on my ramps and topping up the radiator with the engine running high revs but wouldn't have any of that so replaced the cap as I was slowly losing coolant. There is coolant coming out the overflow pipe now when hot so will now get a new cap. This cap has 7psi on it, is that correct. I'm going to drain the system and disconnect the heater unit and see if I have a flow through the heater unit and what colour the coolant is.
Regards Terry H
 
If you didn't leave an air gap under the cap it will push coolant out through the overflow as there isn't any room for the coolant to expand as it gets hot.

If you have flow into and out of the heater rad, that doesn't mean thet the matrix is clear.
 
You can bleed the matrix by loosening the hose clip on the top hose going into the heater matrix with the engine running and the radiator cap on, once you see a solid stream of coolant coming out the joint, tighten the clip agai. be careful as there will be hot coolant. Lett me know if that works for you.
 
Well its not an air lock then if you got it full and it is now finding its own level.

H
I agree that he can have flow and no heat, but in an earlier post he said he had cold hoses, so I was working on the assumption that he had a blockage to sort.
But we all know assumptions are the ............. of all .... ups.
 
I've just ordered a new heater top and bottom hose along with a new radiator cap so will be waiting for those to arrive before proceeding with the heater problem. I noticed that the bottom hose was bound up with tape and the top hose was very stiff like it had been on there a while. So will give it a good go when I get at it.
Regards Terry H
 
Hi all,
While I have the carbs off I decided to replace the top and bottom heater hose. While I have the old ones off I tried poring water through the bottom hose with a suitable long hose on the bottom pipe to get the end above the top hose, to see if it would run out the top hose, but it didn't. I then tried blowing through the bottom hose to see if I could get the water to come out the top, but I couldn't blow through it. I then tried poring water in the top hose to see if it would run out the bottom and it did. I tried blowing through the top hose and I could blow with a little bit of a restriction. I've now filled the heater with vinegar and will leave it until tomorrow and try to see if I can get water through again. Any comments welcome and which way does the coolant circulate, does it go in the top and out the bottom or the other way round.
Regards Terry H
 
Well, that’s a new one! Do either of the hoses look partially collapsed? I’ve had a similar problem years ago with a flex hose to the rear caliper. It would open under pressure than close afterwards causing the calipers to stick.
Otherwise it sounds like something huge is stuck inside acting like a check valve.

My money is on the hoses, worth replacing if you haven’t already. In my case I used a special coil on the outside of the hose to stop it collapsing when bent. See pic.
 

Attachments

  • DE548DD7-2D7E-43FD-AD27-265D53F41BBA.jpeg
    DE548DD7-2D7E-43FD-AD27-265D53F41BBA.jpeg
    587.9 KB · Views: 13
New hoses so not a problem with those, (I did say I was replacing them), and they are the only hoses connected to the heater, heater is now isolated from the rest of the system. Will check again in the morning. Oh and I hope everyone is OK with this virus about.
Regards Terry H
 
New hoses so not a problem with those, (I did say I was replacing them), and they are the only hoses connected to the heater, heater is now isolated from the rest of the system. Will check again in the morning. Oh and I hope everyone is OK with this virus about.
Regards Terry H

Trying not to go stir crazy after 6 weeks of lock down, but hanging in there. Most issues on my car are fixed because of boredom :).

With the blockage have you tried putting the hose on the bottom (blocked) hose leaving water pressure on and probing the top outlet of the matrix? See if that allows some water out.
 
Haven't had a garden hose with mains water near it yet, just trying to get a flow through without pressure. What I did was put a hose with a plastic funnel on the bottom heater pipe that put the other end higher than the top pipe and pored water into the hose from a gallon container, so no pressure on the heater box yet, (baby steps), and no water came out the top pipe. I then did the same with the top pipe with no hose on the bottom pipe and had a small flow of water from the bottom pipe. So there is a blockage in there but it seems to allow a flow one way. That's why I put the vinegar in the heater box hoping to dissolve the crud that's in there, I did have thoughts on cheap Cola.
Regards Terry H
 
You should be ok with mains water pressure. If it does leak [with a hose pipe connected] you saved it failing in service. But the lack of flow is a bit of a smoking gun for sure. Especially as the matrix has a bypass path for water if the core is blocked.
 
I'll be putting the garden hose on it tomorrow morning and flush the engine and the heater separately. Fingers crossed all will be OK.
Regards Terry H
 
Update. I put the garden hose on the top heater pipe this morning and flushed out the vinegar, better water movement than yesterday. I then put the garden hose on the bottom heater pipe and had a better trickle on the top pipe than yesterday but still not perfect, so there is a blockage there somewhere.
As there is a flow both ways I decided to live with it a while and see if the coolant flow will clear it over time. On filling the system with only the bottom hose between the engine and heater attached I was expecting to see coolant trickle out the top heater pipe but the filler on the radiator is lower than the heater top hose. It would make much more sense to have the filler higher than everything else. Have to try and get the filler higher with the jack. as I don't have the carbs on it yet.
Regards Terry H
 
To much lime scale What about bicarbonate of soda with a mix of white vinegar that should be stronger to get rid of the lime scale
 
sounds like heater matrix is choked . I am in process strippings. mice and have it out on bench now .lot of foam has disintegrated. its a V8 so no need to remove a rocker cover though I found removing throttle bracket. greatly assist. unit removal and did need a lever as it had 'stuck' a bit over the years. 4 bolts holding unit in and 4 wires near steering box for blower motor .be sure. to mark these up before disconnecting! heater levers. were discounted ( two have partial breakages on fork parts ! ) did notice when boa was on bench the upper main air flap was stuck! even though lever was moving full back and forth wad not working it. investigation found it wa stuck by friction due to upper part where mesh is being slightly crushed down keeping it in place. quick leverage with toll and all well ;) good luck I might try and upload a couple ope pics later if anybody is interested ?
 
"I might try and upload a couple ope pics later if anybody is interested ? "

Can't do any harm. A few photo's of a heater box taken apart will be better than the exploded diagram in the manual.
Regards Terry H
 
Back
Top