Thanks Drover - the mininum flow rate without the pump stopping on me is 4 Lpm . At this all 5 burners fire up on the display (set at 50 degrees max.) Managed to get 33 degrees this time but tank water temp. is now 18 degrees. Any increase in the flow rate from here and the temp will drop. Cant find a tempering valve (nothing under van) and enclosed cabinet inside. The water was quite hot when we first got the van but significantly down now - thinking perhaps a temp probe? but only guessing as i dont really have a clue! Will keep playing around with flow rates etc and see if i can get any improvement.
Adjust suburban hot water system
- Thread starter Adam G
- Start date
This is interesting for sure, 50 deg isn't really all that hot to some, I know as our house temp valve set at 53 was damn cold I thought, things improved when I did surgery on it........................
It's an interesting problem, I'm doing some 101 on this system to find out more, one interesting thing I came up with in the documents on it is in the pic, more research needed and will ask some folks around here if they have one fitted, every second house has a boat and van here..........
It would actually seem that you may have to insulate your HW lines to try and keep the temp up as much as possible and the temp prbe could be reporting a false, if you can check the contact on the temp probe, any bit of resistance on the contacts will give a false reading, remove it and give it a clean in some descaler, like a coffee machine, this may help but if your temp at the tap is about 45 deg or so I think that may be all you get.... unless theres a way tochange the default temp setting..................
PS: there is a cold water temp probe and a HW one.....
It's an interesting problem, I'm doing some 101 on this system to find out more, one interesting thing I came up with in the documents on it is in the pic, more research needed and will ask some folks around here if they have one fitted, every second house has a boat and van here..........
It would actually seem that you may have to insulate your HW lines to try and keep the temp up as much as possible and the temp prbe could be reporting a false, if you can check the contact on the temp probe, any bit of resistance on the contacts will give a false reading, remove it and give it a clean in some descaler, like a coffee machine, this may help but if your temp at the tap is about 45 deg or so I think that may be all you get.... unless theres a way tochange the default temp setting..................
PS: there is a cold water temp probe and a HW one.....
Attachments
Last edited:
Would be interested to see what temps others get in there systems. Further testing may reveal something to people smarter than me - Tank water at 15 degrees/ flow rate 4 LPM.
Set control at 35 degrees -activates 2 burners to achieve 33.4 degrees.
Set control at 50 degrees -activates 5 burners to achieve 36 degrees.
I am still trying to work out how to get at temp probe as a lot of screws to remove in relatively confined space.
@Gero , from someone who does not even have a water heater, here is an idea from way out in "left field"! Just because the burners fire up does not indicate that the gas is burning as hot as it should, or even if the gas pressure and feed is as it should be. I had a similar problem with my 3 way fridge when operating on gas. I found that the burner was corroded and the slots were not as good as they could have been. After removing burner for cleaning with brass brush, and cleaning out the gas line (checked the fine gas filter in the jet for gas too), all was fine again and the flame sounded like a budsen burner I used in the chemistry lab when at school. So it must have improved the gas to air ratio for better/hot combustion. Improved fridge operation considerably. In fact, fridge manual mentions that burner and gas jet should be checked annually...........
I have also been involved in fixing another vanner's gas operation for their 3 way fridge. There was a poor blue flame and very weak pressure. Not surprising considering that the van was 10 years' old and did not appear to have had any gas maintenance!! Spoke to my Son-in law plumber/gas fitter, and he confirmed that low gas flame could originate from gas regulator not operating properly - partially blocked or pressure not set correctly after years of use. I also understand that the inside of some of the flexible gas lines can get "gunky" partially blocking inside of regulator and not perform properly. There has been a mention by a member on this forum about lack of heating for his webber barbecue when connected to the standard gas lines in his van too. May be time to check burners (can you do that??) and perhaps getting gas pressure checked?? Just a thought that might be useful.
@Boots in Action -When I took it to jayco agent before telling me there was nothing wrong with it , they did blow out gas lines and checked regulator apparently.Although they wouldn't had have it long enough to check burners or much else. You could still be onto something but as far as getting to burners it does seem very difficult to get to without a fair bit of dismantling first. I do seem to be eking out a few more degrees every time i use it so perhaps a long burn may do some good. I am trying to get an acceptable result at 4 LPM as this is the minimum the pump will run at but if i do attach the tap to van and run at 3.2 LPM the results are much better( 40 degrees). Still gives me food for thought as i do get a bit sidetracked in one direction quite often.
While I think its not possible to view the burners looking at the book unless you strip it right down, I think if you can hear the extra burners fire up or an increase in heat from vent that will be an indicator of working or not, I doubt the monitor screen would know if they are working ,more like the command to the solenoid to open is displayed, whether the solenoid is actually opening would be the thing, only a flame sensor for no flame no other sensor there.
Change gas bottles may do something, has worked for me on other things and I have no idea why....
Tyre Kick List:::::::::: Water flow good, low temps within parameters, Increase temp setting, no faults indicated but no increase in temp.
So does point to no extra burners activating meaning blockage or a dodgy solenoid..................(light ON)...................... Unless something has got into the heat exchanger and built a big nest blocking the core, like a grass choked radiator, now there is a thought, that could explain why the heat is slowly improving over time as the nest is burning/falling away. a mud wasp could enter via the vent, past the fan and a heat exchanger is a top line house for them....... the system would be working, no faults to show, just a mud brick house insulating the water core...... its an idea anyway
Either way a dismantle I think ................................. it has a condensation drain you may be able to get at it and poke with a bit of whipper snipper line to see if any muck in the box ??????????/
Change gas bottles may do something, has worked for me on other things and I have no idea why....
Tyre Kick List:::::::::: Water flow good, low temps within parameters, Increase temp setting, no faults indicated but no increase in temp.
So does point to no extra burners activating meaning blockage or a dodgy solenoid..................(light ON)...................... Unless something has got into the heat exchanger and built a big nest blocking the core, like a grass choked radiator, now there is a thought, that could explain why the heat is slowly improving over time as the nest is burning/falling away. a mud wasp could enter via the vent, past the fan and a heat exchanger is a top line house for them....... the system would be working, no faults to show, just a mud brick house insulating the water core...... its an idea anyway
Either way a dismantle I think ................................. it has a condensation drain you may be able to get at it and poke with a bit of whipper snipper line to see if any muck in the box ??????????/
Gero, what you have identified is that the instantaneous gas water heater needs two things to achieve temperature, incoming water temp and flow.
Also to clarify a statement in one of the above posts, a good gas flame is a blue flame, orange flame has to much fuel an is considered a carbonising flame, all flare and minimal heat value.
The whole basis of the instantaneous heater is to raise the the temp of incoming water. To do this the heater will have a flow control valve built in. The heater will only burn at one temperature and so as demonstrated in the chart that Drover posted, the colder the water temperature the slower the flow needs to be to achieve a greater rise in water temperature.
This concept works really well on our home Rinnai water heaters as the heater is both more sophisticated, and most households have consistent flows. For the caravan playing around with flow results in wasted water.
ive been buggering around with my Camec heater for a while and are extremely dissatisfied with it. I am onto my second version after the first generation one was ordinary at best. Camec was helpful but only because being a gas fitter/ plumber i conducted fault finding missions for them and frustrated I got given the new version.
On pump pressure I remove the strainer from tap outlet to assist in getting adequate flow to trigger the burner lighting, town water is marginally better. I am contemplating installing a Redwater valve to recirculated the water until a sufficient temp has been achieved.
Also to clarify a statement in one of the above posts, a good gas flame is a blue flame, orange flame has to much fuel an is considered a carbonising flame, all flare and minimal heat value.
The whole basis of the instantaneous heater is to raise the the temp of incoming water. To do this the heater will have a flow control valve built in. The heater will only burn at one temperature and so as demonstrated in the chart that Drover posted, the colder the water temperature the slower the flow needs to be to achieve a greater rise in water temperature.
This concept works really well on our home Rinnai water heaters as the heater is both more sophisticated, and most households have consistent flows. For the caravan playing around with flow results in wasted water.
ive been buggering around with my Camec heater for a while and are extremely dissatisfied with it. I am onto my second version after the first generation one was ordinary at best. Camec was helpful but only because being a gas fitter/ plumber i conducted fault finding missions for them and frustrated I got given the new version.
On pump pressure I remove the strainer from tap outlet to assist in getting adequate flow to trigger the burner lighting, town water is marginally better. I am contemplating installing a Redwater valve to recirculated the water until a sufficient temp has been achieved.
Thanks @rags so when I have time I will see if I can take one side off the cabinet to check the flame for my own satisfaction. So are the water temp figures in the table that @Drover posted to be taken with a grain of salt ? ( perhaps like car manufactures fuel economy figures). In that they are reading higher than can be achieved in reality. I have a better understanding now of instantaneous heaters and there limitations, particually when the tank water gets much colder during winter. May even owe my jayco man an apology yet.(Perhaps)
Just had a shower and 36 degrees is ok, just don't want to slow the water flow down too much to achieve it. Still would like others with same system to let us know how they are finding it .Thanks.