Coach engine heat

[Daniel E Golub]

Dear Sirs,
My 1988 coach heater doesn't make any heat, there is water runing thru however at the front radiator but heat is barely noticeable.
Might be the heating core is pluged or needs a pump? The engine runs at 170 F.
Sincerely
Dan

[TechTalk]

There are two water valves to open in the winter for proper heater operation and close in the summer for complete shutdown. You should check that both valves are fully open for heater operation. The valves are located on the driver's side of the engine. One valve is easily visible just above the frame and forward of the fan. The other valve, although difficult to see, is located below the other valve and behind the frame. The system is also equipped with a booster pump. The pump operates only when the temperature control lever on the dash is moved to the far right. This should activate the booster water pump located forward of the right front tire. You should be able to hear the booster pump running. If not, check to insure it is getting 12 volts. If the pump is not operating and you can't determine the cause, you can acquire a replacement pump from the Newell Parts Department, 1-888-363-9355. If you are not successful in repairing or replacing the pump, the pump should be removed as it creates a restriction when not running. Removal will improve heater performance, but not to the level achieved when the pump is operating as designed.