B Series has no heat!

[vinnie07]

on his Model you need to pull the dash to change the core.....He should backflush like I suggested and hope a bunch of crap comes out

Thanks for the advice! I'll give it a try as soon as it warms up. I'm hoping a bunch of crap comes out too. I'll keep you posted on my progress.

 

[MMRanger]

It happened to me once, it turned out that my aftermarket heater hose ends have melted... After I had my new Heater Core replaced and cheaped out on other parts like them hoses. I opted for an OEM Heater Hose.

After market, never again.

 

[vinnie07]

I have an update...the weather has been warm here lately and all of a sudden the Mazda has heat! I'm confused....All I did was replace the T-Stat and put new coolant in, but it had no heat when it was cold here. So I'm pretty much ruling out a clogged heater core as being the issue, but could the heater control valve be getting stuck closed position when it's cold? Should I replace it? Has anyone else ran into this issue? Any advice would be appreciated! Thanks!

 

[modelageek]

Vinnie. Did youever backflush the core? What makes you think the heater control valve is bad?

 

[vinnie07]

No...I didn't get a chance to back flush the heater core yet. I was going to do that today, per your suggestion in an earlier post. I'll do the back flush next time I can take a look at the truck. The heater control valve was my last place to check to make sure it's working properly. I'll keep you posted on my progress. Thanks again for all the help!

 

[modelageek]

No...I didn't get a chance to back flush the heater core yet. I was going to do that today, per your suggestion in an earlier post. I'll do the back flush next time I can take a look at the truck. The heater control valve was my last place to check to make sure it's working properly. I'll keep you posted on my progress. Thanks again for all the help!

I believe you told us that you tested the hose at the spot were it enters the firewall and it was HOT. I think you told us that you tested the hose coming out of the firewall and it was cold. this indicates that your engine temp is fine, your heater control valve is fine and that your heater core is clogged. backflush it and pray