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[Andy B]

Had a look after work today i just noticed two pumps as in winter pack i think.One is next to the expansion tank and theres another on the right side of the rad.After a drive i turned off the car then turned on to first position no engine start and the cabin heat stayed the same.i suppose as well as the hbv id better check if they are working.What voltages are expected and do they shut the flow off.On a good run today car was spot on the gauge and the matrix pipes were red hot so you couldnt touch them.The one next to the expansion tank flows on an L.

The two pumps you've found has no bearing on the temp of the heater.

The one by the expansion tank is, as you say part of the heater pack, but is only there so that you can run the heather (for about 30 mins IIRC) while waiting for someone without the need to run the engine.

The pump by the rad is there to circulate coolant when you switch the engine off ... to dissipate heat from the block.

[Nick W]

Had a look after work today i just noticed to pumps as in winter pack i think.One is next to the expansion tank and theres another on the right side of the rad.After a drive i turned off the car then turned on to first position no engine start and the cabin heat stayed the same.i suppose as well as the hbv id better check if they are working.What voltages are expected and do they shut the flow off.On a good run today car was spot on the gauge and the matrix pipes were red hot so you couldnt touch them.The one next to the expansion tank flows on an L.

blocked matrix.


The electric pumps only work with the engine off, and the system is only effective while there is enough heat in the coolant.


Checking the vacuum connections to the HBV is worth doing, but if they're correct, and the hose to it is hot then the water isn't flowing through the matrix.


So, I'll write it again:


BLOCKED MATRIX!!

[Andy B]

Had a look after work today i just noticed to pumps as in winter pack i think.One is next to the expansion tank and theres another on the right side of the rad.After a drive i turned off the car then turned on to first position no engine start and the cabin heat stayed the same.i suppose as well as the hbv id better check if they are working.What voltages are expected and do they shut the flow off.On a good run today car was spot on the gauge and the matrix pipes were red hot so you couldnt touch them.The one next to the expansion tank flows on an L.

blocked matrix.


The electric pumps only work with the engine off, and the system is only effective while there is enough heat in the coolant.


Checking the vacuum connections to the HBV is worth doing, but if they're correct, and the hose to it is hot then the water isn't flowing through the matrix.


So, I'll write it again:


BLOCKED MATRIX!!

You're sat on the fence then Nick 

[Nick W]

Had a look after work today i just noticed to pumps as in winter pack i think.One is next to the expansion tank and theres another on the right side of the rad.After a drive i turned off the car then turned on to first position no engine start and the cabin heat stayed the same.i suppose as well as the hbv id better check if they are working.What voltages are expected and do they shut the flow off.On a good run today car was spot on the gauge and the matrix pipes were red hot so you couldnt touch them.The one next to the expansion tank flows on an L.

blocked matrix.


The electric pumps only work with the engine off, and the system is only effective while there is enough heat in the coolant.


Checking the vacuum connections to the HBV is worth doing, but if they're correct, and the hose to it is hot then the water isn't flowing through the matrix.


So, I'll write it again:


BLOCKED MATRIX!!

You're sat on the fence then Nick 

it isn't a complicated problem to diagnose.
But DIYers as a rule prefer to faff about only doing half of the wrong job rather than spend a few minutes doing intelligent fault finding.
Access to the internet encourages this.

[gavlar001]

Point taken. I'm gonna flush the matrix though and I really do appreciate all the input from more experienced mechanics and car owners as I wouldn't have got this far with it. Although I am really enjoying the car so far as a 2nd car. Will keep you posted Many thanks again Gavin

[Doctor Gollum]

Point taken. I'm gonna replace the matrix though and I really do appreciate all the input from more experienced mechanics and car owners as I wouldn't have got this far with it. Although I am really enjoying the car so far as a 2nd car. Will keep you posted Many thanks again Gavin

Fixed

[Nick W]

Point taken. I'm gonna flush the matrix though and I really do appreciate all the input from more experienced mechanics and car owners as I wouldn't have got this far with it. Although I am really enjoying the car so far as a 2nd car. Will keep you posted Many thanks again Gavin

consider flushing the matrix as more diagnosis rather than fixing the fault: I suspect it will only make a small improvement to the heater's output. If that's the case, you will have proved you need a new matrix. The heater should provide copious HOT air continously.


While you have the heater hoses disconnected, it's worth applying some vacuum to the HBV and checking that it is actually working.

[Entwood]

If memory serves .. vacuum turns the HBV off .. so disconnect the plastic vac pipe and block it with a small screw leaving the HBV side open, a serviceable HBV defaults to max flow ("on") .. this "might" assist the water flow if the matrix is not blocked, it was how I diagnosed a failed vac relay thingie behind the glove box some years back !!

[gavlar001]

  mega heat in the cabin again now.You were all spot on, it was a combination of open stat and a blocked heater matrix.I flushed and back flushed the matrix today and when i backflushed it the flow started to stop then all of a sudden all this crud came flying out.Its in good condition as it wasnt really corrosion it was mainly silt and small fine particles. I think it might need a hbv as well, as i disconnected the vac pipe after flushing and then refilling it and it was mega warm, but as soon as i plugged it back on the hbv it seemed to effect the heat. Still will replace it temp gauge and car now heating up correctly and sitting at correct temp, cabin full of heat lol.Many Thanks Gavin 

[YZ250]

Nice one.    Glad you are nearly sorted.