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graearea
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Heater bypass bypass

It seems to me that the bypass for my heater matrix is not stopping the coolant from getting through and I end up with a roasting heater when I want some cold air coming in to cool the footwell. The valve seems all the way closed with the cable all the way in. Is there a better way of doing this? Not looking forward to getting incinerated again. 

Do I drop out the coolant and put a hose from the top to the bottom and live without a heater for a couple of months?

Jonathan Kay
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The cable not closing the valve fully is a common fault. 

A faulty valve not closing doesn't seem to be. 

I'd take it out and have a good look and play by hand. And if it can't be persuaded to close then replace it.

Connecting the top and bottom hoses directly until it's sorted should work fine.

Jonathan

SM25T
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The valve is from a TX1 taxi .... cheap from eBay suppliers.

SLR No.77
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Ian, an eBay search returns a simple inline heater valve for TX1 taxis, however doing a search for a heater control for a TX2 .....

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SM25T
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Aha ... memory .... I knew it was a TX something

AdrianC
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I have had a similar issue. First of all check the hoses to the valve are the correct way round. The bottom hose to the valve should come from the back of the head, the top hose returns the coolant. The top of the valve is a straight through connection on the valve ie the valve only operates on the bottom of the valve only (supply). There will always be some heat "bleed" through the top connection.

The valves do have a habit of over time letting a small amount of hot water through but it is enough to put significant heat into the heater matrix. I have had 2 faulty valves over the last 5 years.

Changing the valve is simple and cheap.

graearea
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how do I find out what kind of tubing that is so I can put a loop in. it doesn't look like there's enough there to do it. is it in a build manual or something?

thanks all!

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SM25T
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It is 16mm bore heater hose. Just remove both from valve and join them together, preferably with a barbed straight hose connector. If on tour, a short bit of 15mm copper tube will do .... Both options with hose clamps of course.

AdrianC
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In a few weeks time with cooler weather you will probably be reversing this and reconnecting the heater but still with the same problem. Surely far better to replace the valve, speak to Chris @Redline Components, he has them in stock and nearly always next day delivery.

If you raise the car as high as possible at the rear and syphon all the water out of the expansion tank you will have little water in the heater matrix to clear up after disconnection. After any changes lower and refill expansion tank.

StevehS3
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With the control pushed in fully and the valve against its stop I still get slightly warm air. I wasn't sure if it was simply warm outside air but I think the valve is passing slightly. 

graearea
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nice tip Adrian. thanks.

I'll replace the entire thing. they're pretty cheap.

in the mean time I'll find some 5/8" /16mm tube and just connect one to the other I think.

thanks all

 

UFO 7 WTF , 3d printed stuff and self cancelling indicators