Chargerman Posted February 7, 2021 Share Posted February 7, 2021 The loop from the engine is separate from the loops that run to the house heat exchanges. Therefore, the heat can work fine on diesel or electric but when running off the engine when going down the road it is possible that the engine antifreeze is not circulating through the Aquahot which will cause what the OP is experiencing. Hopefully we will here back from him soon to see if he’s had any luck finding the issue 1 Link to comment Share on other sites More sharing options...
Texomaman73 Posted February 7, 2021 Share Posted February 7, 2021 You are right Chargerman! I thought his original post stated that it was just one zone that wasn't working on engine heat, but I went back and re-read it and it clearly states no vents were working. I confused his post with another that was talking about two zones working and the third not. Thanks for pointing out my error! 1 Link to comment Share on other sites More sharing options...
waterskier_1 Posted February 7, 2021 Share Posted February 7, 2021 On 2/5/2021 at 5:02 PM, Chargerman said: I think I would pull one of the hoses that come from the engine off of the Aquahot. Then I would attach a short length of hose to it so I could get the end elevated higher that the hose run. Then I would dump a good amount of antifreeze into it, pinch it and reconnect it to the Aquahot and fire up the engine and see if it gets warm after a bit. Also, if your Coach has the engine preheat option on the Aquahot I would turn that on at the same time to aid in getting the circulation going My manual specifically states to ensure that the engine preheat is OFF when the engine is running. The rationale is the engine pump is much stronger than the preheat circulation pump and could damage the preheat circulation pump. I've forgotten a couple times when first firing up the engine, but soon notice as I'm checking gauges during warmup. Link to comment Share on other sites More sharing options...
96 EVO Posted February 7, 2021 Share Posted February 7, 2021 1 hour ago, waterskier_1 said: My manual specifically states to ensure that the engine preheat is OFF when the engine is running. The rationale is the engine pump is much stronger than the preheat circulation pump and could damage the preheat circulation pump. I've forgotten a couple times when first firing up the engine, but soon notice as I'm checking gauges during warmup. Yeah, I don't know if that will actually damage the pump. There was plenty of owners on IRV2 that thought the pre-heat pump had to be running to get engine heat going down the road. Never heard any of them complaining they were constantly replacing the pump. Link to comment Share on other sites More sharing options...
Dr4Film Posted February 7, 2021 Share Posted February 7, 2021 I happen to be one of them that will have the Engine PreHeat switch on sometimes while driving and here is why. Over the years of road travel there were numerous times after driving for a number of hours we would pull into a rest area and once outside I would hear the Aqua-Hot diesel running. So now when I think of it I will flick the switch on and run with the PreHeat pump circulating the hot engine fluid through the Aqua-Hot. When doing so I have never heard the Aqua-Hot running when we pull into a rest area or stop for the night. I haven't replaced that pump or for that matter any of the Aqua-Hot pumps. BTW, that PreHeat pump ran 24 hours a day for almost ten years as the factory had wired the PreHeat switch incorrectly such that when I thought the switch was turned off (indicator light OFF) the pump was on and when the switch indicator light was on the pump was OFF. Go figure! In 2011 when I discovered this I removed the switch and had to completely rewire the switch adding a new wire as it wasn't just swapping wires there was one wire actually missing. Link to comment Share on other sites More sharing options...
waterskier_1 Posted February 7, 2021 Share Posted February 7, 2021 Ben, I'm not advocating second guessing the manufacturer's recommendation - I feel if they put that in the manual (thinking more about it, it was probably in the Aquahot manual, not the Monaco Owner's Manual) there would have to be a overwhelming reason to disregard. Link to comment Share on other sites More sharing options...
96 EVO Posted February 7, 2021 Share Posted February 7, 2021 2 minutes ago, waterskier_1 said: Ben, I'm not advocating second guessing the manufacturer's recommendation - I feel if they put that in the manual (thinking more about it, it was probably in the Aquahot manual, not the Monaco Owner's Manual) there would have to be a overwhelming reason to disregard. I hear ya! I leave mine off going down the road as well. Link to comment Share on other sites More sharing options...
Guest Ray Davis Posted February 7, 2021 Share Posted February 7, 2021 (edited) 10 minutes ago, Dr4Film said: I happen to be one of them that will have the Engine PreHeat switch on sometimes while driving and here is why. Over the years of road travel there were numerous times after driving for a number of hours we would pull into a rest area and once outside I would hear the Aqua-Hot diesel running. So now when I think of it I will flick the switch on and run with the PreHeat pump circulating the hot engine fluid through the Aqua-Hot. When doing so I have never heard the Aqua-Hot running when we pull into a rest area or stop for the night. I haven't replaced that pump or for that matter any of the Aqua-Hot pumps. BTW, that PreHeat pump ran 24 hours a day for almost ten years as the factory had wired the PreHeat switch incorrectly such that when I thought the switch was turned off (indicator light OFF) the pump was on and when the switch indicator light was on the pump was OFF. Go figure! In 2011 when I discovered this I removed the switch and had to completely rewire the switch adding a new wire as it wasn't just swapping wires there was one wire actually missing. We have really enjoyed using our aqua hot while driving but I can't say I know if the burner was coming on or not. I'll try to remember to check that out, thanks Edited February 7, 2021 by Ray Davis Link to comment Share on other sites More sharing options...
96 EVO Posted February 7, 2021 Share Posted February 7, 2021 If It's cold enough out while traveling, I'll run the diesel burner. Residual heat from the engine just doesn't cut it when it's below freezing! I compare the heat you get out of the exchangers with only the engine heating the boiler fluid, to what I get with the single 1650W element. Link to comment Share on other sites More sharing options...
Guest Ray Davis Posted February 7, 2021 Share Posted February 7, 2021 4 hours ago, 96 EVO said: If It's cold enough out while traveling, I'll run the diesel burner. Residual heat from the engine just doesn't cut it when it's below freezing! I compare the heat you get out of the exchangers with only the engine heating the boiler fluid, to what I get with the single 1650W element. Yeah Ben but you up there in that cold north country. I'm down here in Tex where 40 deg f is cold to me. I don't do cold very well, don't do hot so well either. It's hard to find it just right but I'm still looking. LOL Link to comment Share on other sites More sharing options...
96 EVO Posted February 7, 2021 Share Posted February 7, 2021 Second winter in a row I haven't gotten south ☹️! Cummins is getting restless! It loves those 2500mi runs without cooling down! Link to comment Share on other sites More sharing options...
Guest Ray Davis Posted February 8, 2021 Share Posted February 8, 2021 46 minutes ago, 96 EVO said: Second winter in a row I haven't gotten south ☹️! Cummins is getting restless! It loves those 2500mi runs without cooling down! I feel for ya lock in way up there. We haven't been anywhere either, covid, shoulder surgery, drs appointments , getting old sucks but I'll take it. We need to get this covid gone. How is the vaccine going up there? Down here it's a mess, hard to get an appointment, but we finally did. Link to comment Share on other sites More sharing options...
96 EVO Posted February 8, 2021 Share Posted February 8, 2021 6 minutes ago, Ray Davis said: How is the vaccine going up there? Slower than your's! We've been practically cut off of supply by both manufacturers for most of Feb. Link to comment Share on other sites More sharing options...
Guest Ray Davis Posted February 8, 2021 Share Posted February 8, 2021 Just now, 96 EVO said: Slower than your's! We've been practically cut off of supply by both manufacturers for most of Feb. That's too bad they may not let you travel until you get the vaccine. Looks like our aliens are getting it so maybe you could slip on down and get in line LOL Link to comment Share on other sites More sharing options...
96 EVO Posted February 8, 2021 Share Posted February 8, 2021 Well, they are still 'claiming' we can all be vaccinated by Sep. Link to comment Share on other sites More sharing options...
96 EVO Posted February 8, 2021 Share Posted February 8, 2021 Sorry about the brief hijack Woody! We're waiting for more information. Link to comment Share on other sites More sharing options...
Guest Ray Davis Posted February 8, 2021 Share Posted February 8, 2021 Oh yeah forgot about Woody, sorry Woody. Link to comment Share on other sites More sharing options...
Chargerman Posted February 8, 2021 Share Posted February 8, 2021 49 minutes ago, Ray Davis said: Oh yeah forgot about Woody, sorry Woody. Hopefully he will chime back in soon to update us. Link to comment Share on other sites More sharing options...
96 EVO Posted February 8, 2021 Share Posted February 8, 2021 50 minutes ago, Chargerman said: Hopefully he will chime back in soon to update us. Yeah, I like your idea of swapping hoses first. If the pump can only freewheel in one direction, that could be the problem. Link to comment Share on other sites More sharing options...
Dr4Film Posted February 8, 2021 Share Posted February 8, 2021 I'd bet my next stimulus check that Roger Berke or even John Carrillo would have the answer to Woody's problem in a heartbeat. Plus they would know whether the Motorade Pump is a free wheeling pump or not. 1 Link to comment Share on other sites More sharing options...
Woody O Posted February 8, 2021 Author Share Posted February 8, 2021 On 2/7/2021 at 8:29 AM, Chargerman said: The loop from the engine is separate from the loops that run to the house heat exchanges. Therefore, the heat can work fine on diesel or electric but when running off the engine when going down the road it is possible that the engine antifreeze is not circulating through the Aquahot which will cause what the OP is experiencing. Hopefully we will here back from him soon to see if he’s had any luck finding the issue OK, I finally had a chance to work on the Aqua Hot. First, I gradually removed the engine block hoses from the Aqua Hot one at a time and found that both hoses were full of antifreeze. Then I switched the two hoses and ran the Cummins for 10-15 minutes, getting the engine temp to 160+ and felt the hoses and they were still cold. I even slipped the hose ends back just enough for a slight leak and felt the antifreeze and it was cold. I then went inside and turned the engine off and turn on the engine preheat for 5-10 minutes. I could hear the Aqua Hot pump running, but didn't notice warm hoses when I felt them. Any more ideas? Link to comment Share on other sites More sharing options...
Guest Ray Davis Posted February 8, 2021 Share Posted February 8, 2021 Maybe one or both hoses are kinked . How much of them can you see? I would take it back to the shop and ask them to look at it. Link to comment Share on other sites More sharing options...
trailmug Posted February 8, 2021 Share Posted February 8, 2021 I wonder if there's air at the top of the coolant loops. The loop resembles a rope (copper tubing) wrapped around a barrel (boiler tank). I'd be tempted to take the return line off, put it in a bucket, and run the engine for a bit to try to purge the loop. Then obviously return the coolant to the surge tank. Link to comment Share on other sites More sharing options...
k7jv Posted February 8, 2021 Share Posted February 8, 2021 About all that it could be would be some kind of a restriction in the engine loop. The ONLY things that were touched were presumably the two hoses, right? A check valve not opening? (if there is one, and if the hoses were reversed at one end or the other) A restriction, or kink in one of the runs they installed? The engine pre-heat zone pump in the AquaHot chose this exact time to seize? Or they could have let some kind of debris or something in the inlet line that worked its way into the pump and stalled the impeller causing a restriction. Two thoughts on this one. Those pumps are not shaft driven. The impellers are magnetically coupled to the drive motor thru the walls of the two enclosures. Second, I don't recall the exact design of the impeller as to whether stopping it from turning would stop the coolant flow or just slow it a bit. Before pulling lines to "prime" them, can you pull both at the engine end and see if you can blow compressed air thru the entire loop, perhaps in both directions? I think you'd only be talking about a couple of liters of ENGINE COOLANT. (This loop does NOT contain AquaHot boiler fluid). You could even take them loose at the AquaHot end first and then the engine end, and capture what is in the lines and re-use it if you don't have any to replace it. (By blowing both directions you could confirm the possible presence or absence of a check valve. That would tell you whether you would need to swap the hoses.) I would not expect to have to prime the lines. The "Engine Heat" only powers the zone pump. That is not in play in the situation Woody O is facing. It doesn't sound like you've torn into anything with tools, yet, and if true, hopefully the task will be minima if and when you dol. I hope this doesn't become a real monster for you, but I actually don't think that it will, especially if you are able to get to the engine end of the hoses relatively easily, and if you are able to do what you need to do without spreading anti-freeze all around the neighborhood. If you need to remove a hose and keep fluids in it, you can use a pair of needle-nose ViseGrip pliers to pinch off the hose prior to removing it. I've done that many times and it works really well. Good luck!! Link to comment Share on other sites More sharing options...
96 EVO Posted February 8, 2021 Share Posted February 8, 2021 2 hours ago, Woody O said: OK, I finally had a chance to work on the Aqua Hot. First, I gradually removed the engine block hoses from the Aqua Hot one at a time and found that both hoses were full of antifreeze. Then I switched the two hoses and ran the Cummins for 10-15 minutes, getting the engine temp to 160+ and felt the hoses and they were still cold. I even slipped the hose ends back just enough for a slight leak and felt the antifreeze and it was cold. I then went inside and turned the engine off and turn on the engine preheat for 5-10 minutes. I could hear the Aqua Hot pump running, but didn't notice warm hoses when I felt them. Any more ideas? Woody, may not make a difference, but I would have run the engine till it got to over 185, and the thermostat opened. Just thinking maybe coolant is restricted from flowing thru that loop until the thermostat opens. Link to comment Share on other sites More sharing options...
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