Omega Owners Forum

Omega Help Area => Omega General Help => Topic started by: gavlar001 on 12 January 2020, 22:18:31

Title: All done but still no heat.AHH
Post by: gavlar001 on 12 January 2020, 22:18:31
 >:( finished up this evening under torchlight putting it back together after the stat change.Now the car heats up ok and the temp gauge is fine but still no heat in the cabin.Wheres the next place to start looking.Many thanks Gavin. :y
Title: Re: All done but still no heat.AHH
Post by: Andy B on 12 January 2020, 22:22:29
air lock in the heater matrix or blocked matrix
Title: Re: All done but still no heat.AHH
Post by: gavlar001 on 12 January 2020, 22:35:12
 8) cool i know i can flush the matrix but how do i clear an airlock.Thanks
Title: Re: All done but still no heat.AHH
Post by: Andy B on 12 January 2020, 22:37:19
8) cool i know i can flush the matrix but how do i clear an airlock.Thanks

squeezing/'burping' hoses usually help moves trapped air. did you have the heater set to 'hot' when you re-filled the system?
Title: Re: All done but still no heat.AHH
Post by: gavlar001 on 12 January 2020, 22:38:45
Yep on hi full on before i replaced the stat both heater matrix pipes were red hot.
Title: Re: All done but still no heat.AHH
Post by: gavlar001 on 12 January 2020, 22:49:18
Maybe its some sort air control thing how do the heater flaps work.when i put it on screen etc i can here the flaps moving directing the air. Before i did the stat once in the car all of a sudden heat started to blow through then it stopped :(
Title: Re: All done but still no heat.AHH
Post by: Andy B on 12 January 2020, 22:53:37
Sorry out of other ideas then ..... I've not had the need to delve to far as I never had heater problems on my Omega  :-\
Title: Re: All done but still no heat.AHH
Post by: gavlar001 on 12 January 2020, 23:06:28
Thanks anyway. I will start by checking if its an airlock.What the best way to bleed it :y
Title: Re: All done but still no heat.AHH
Post by: Andy B on 12 January 2020, 23:14:56
Thanks anyway. I will start by checking if its an airlock.What the best way to bleed it :y

I'd run it & see if the air moves itself. IIRC the heater matrix connections are a quick click connector  :-\
Title: Re: All done but still no heat.AHH
Post by: gavlar001 on 12 January 2020, 23:34:43
Yep will do. Thinking about it now when I was putting the plenuim back on there was this rubber tube small same size as the ones on the rear of the plenuim just dangling behind everything I will have to trace it and find out where its going. All 4 were connected on the plenuim correctly.
Title: Re: All done but still no heat.AHH
Post by: Migv6 le Frog Fan on 12 January 2020, 23:48:30
Sounds like the vac pipe which plugs into the underside of the plenum at the front. Cant remember exactly what its for though.
When bleeding the system leave the cap of the expansion tank.
Title: Re: All done but still no heat.AHH
Post by: Doctor Gollum on 13 January 2020, 00:59:02
Or the hbv one, which ties in with the lack of cabin heat :y

The one you're thinking of generally stays put unless you split the throttle body from the plenum ;)
Title: Re: All done but still no heat.AHH
Post by: gavlar001 on 13 January 2020, 07:45:46
The throttle body vac pipe was plugged in I think this pipe was like what plugs into the back of the plenum. Been out this morning car temp reads good bleed it good with the cap off. What does the little starship enterprise hbv do I saw it when I was stripping it down and how does the vac system work to provide heat. I think someone left them connected the wrong way etc
Title: Re: All done but still no heat.AHH
Post by: gavlar001 on 13 January 2020, 07:49:50
If I can remember the front throttle body pipe was a vac pipe that was connected to a silver thing on the rear of the fuel inlet housing as I remember it running through the fuel rail inlet when I lifted it off. And the radiator heater hoses both top and bottom during the bleeding with the cap off are not even luke warm
Title: Re: All done but still no heat.AHH
Post by: Andy B on 13 January 2020, 07:57:38
The throttle body vac pipe was plugged in I think this pipe was like what plugs into the back of the plenum. Been out this morning car temp reads good bleed it good with the cap off. What does the little starship enterprise hbv do I saw it when I was stripping it down and how does the vac system work to provide heat. I think someone left them connected the wrong way etc
There's a clue in the name  ;) hbv  ..... heater by-pass valve  :y
Title: Re: All done but still no heat.AHH
Post by: Doctor Gollum on 13 January 2020, 08:02:07
If I can remember the front throttle body pipe was a vac pipe that was connected to a silver thing on the rear of the fuel inlet housing as I remember it running through the fuel rail inlet when I lifted it off. And the radiator heater hoses both top and bottom during the bleeding with the cap off are not even luke warm
Then it's not upto temperature, and not bled, which also won't help the heater any ::)

Top hose gets hot once the thermostat is open and the bottom hose won't be hot until the thermostat has been open a while and there's hot water running through the radiator.
Title: Re: All done but still no heat.AHH
Post by: YZ250 on 13 January 2020, 08:40:21
Yep will do. Thinking about it now when I was putting the plenuim back on there was this rubber tube small same size as the ones on the rear of the plenuim just dangling behind everything I will have to trace it and find out where its going. All 4 were connected on the plenuim correctly.

Remember that there's a rubber hose gearbox breather floating loose (intentionally) at the back of the plenum.
Title: Re: All done but still no heat.AHH
Post by: gavlar001 on 13 January 2020, 08:44:15
 ;D lol Andy will order a gm one and replace and check the vacs on that as well. What should be the correct pipe routing in case someone has put them back wrong.
Title: Re: All done but still no heat.AHH
Post by: gavlar001 on 13 January 2020, 09:21:05
Yep that's what the extra pipe is guys it must be the gearbox breather then. I nearly changed the hbv when it was all apart I didnt have one spare.How does the vac work on that and can you buy vac pipe.
Title: Re: All done but still no heat.AHH
Post by: YZ250 on 13 January 2020, 09:22:03
What should be the correct pipe routing in case someone has put them back wrong.

I was merely mentioning the gearbox breather in case you thought it should be attached to something, but it is intentionally floating loose. The two small plenum hoses (rubber, not plastic) are post throttle breather and carbon canister pipe* (*from one of the four pipes at the back of the plenum to the breather box at the back of the engine) but these are not heater related anyway so can't see them getting muddled up.
Just out of curiosity, if you switch your engine off after a run and pull a vac pipe off (one of the plastic pipes with a rubber end piece), do you hear a hiss. You should hear a slight hiss from the air being released from the vac reservoirs. Vac pipe routing is in the maintenance guide if you need to trace where they go to.  :y


Title: Re: All done but still no heat.AHH
Post by: gavlar001 on 13 January 2020, 09:25:13
Nice one well done I've just got a feeling it's a double wammy lol both the stat failing and definitely the lack of vac to the hbv to open the valve
Title: Re: All done but still no heat.AHH
Post by: Nick W on 13 January 2020, 10:50:11
air lock in the heater matrix or blocked matrix




blocked matrix.
Buy a new one(<£20) and prepare yourself for a nasty job grovelling about in the footwell.


You should be getting HOT air from the heater as soon as the engine reaches normal operating temperature, that's less than a mile.


Nylon vacuum pipe can be bought by the metre, and the rubber joiners are readily available
Title: Re: All done but still no heat.AHH
Post by: Doctor Gollum on 13 January 2020, 10:52:53
As long as the Hbv vac is connected/working ;)
Title: Re: All done but still no heat.AHH
Post by: Andy B on 13 January 2020, 11:48:53
;D lol Andy will order a gm one and replace and check the vacs on that as well. What should be the correct pipe routing in case someone has put them back wrong.
It's too long since I had an omega for me to remember  ...  ;)

Dr G will know .... ;)
Title: Re: All done but still no heat.AHH
Post by: cam.in.head on 13 January 2020, 12:08:43
there is also a potential issue where the little operating levers at the side of the heater box can pop off the operating motors .these levers open and close the flaps.both mine had become detached .
Title: Re: All done but still no heat.AHH
Post by: Doctor Gollum on 13 January 2020, 12:27:37
;D lol Andy will order a gm one and replace and check the vacs on that as well. What should be the correct pipe routing in case someone has put them back wrong.
It's too long since I had an omega for me to remember  ...  ;)

Dr G will know .... ;)
hbv vac comes from the vac reservoir in he scuttle and is controlled by the climate panel and a vac switch, also in the scuttle iirc. Not that I have ever changed either...
Title: Re: All done but still no heat.AHH
Post by: Marks DTM Calib on 13 January 2020, 12:54:34
There is a vac pipe schematic in the how to section
Title: Re: All done but still no heat.AHH
Post by: Marks DTM Calib on 13 January 2020, 12:55:24
Here

http://www.omegaowners.com/forum/index.php?topic=90499.0
Title: Re: All done but still no heat.AHH
Post by: gavlar001 on 13 January 2020, 19:45:51
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.
Title: Re: All done but still no heat.AHH
Post by: Doctor Gollum on 13 January 2020, 19:51:26
 ???
Title: Re: All done but still no heat.AHH
Post by: Andy B on 13 January 2020, 20:29:53
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.
Title: Re: All done but still no heat.AHH
Post by: Nick W on 13 January 2020, 21:42:01
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!!
Title: Re: All done but still no heat.AHH
Post by: Andy B on 13 January 2020, 22:14:02
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  ::) ::) ;)
Title: Re: All done but still no heat.AHH
Post by: Nick W on 13 January 2020, 22:36:25
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.
Title: Re: All done but still no heat.AHH
Post by: gavlar001 on 13 January 2020, 23:09:27
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
Title: Re: All done but still no heat.AHH
Post by: Doctor Gollum on 14 January 2020, 03:06:19
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 ::)
Title: Re: All done but still no heat.AHH
Post by: Nick W on 14 January 2020, 11:19:29
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.
Title: Re: All done but still no heat.AHH
Post by: Entwood on 14 January 2020, 13:51:02
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 !!
Title: Re: All done but still no heat.AHH
Post by: gavlar001 on 15 January 2020, 19:20:23
 ;D 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  :y
Title: Re: All done but still no heat.AHH
Post by: YZ250 on 15 January 2020, 19:39:15
Nice one.  :y  Glad you are nearly sorted.