Truma no so hot ? (1 Viewer)

[BusyBuilder]

On our Hymer B544 (2012 model) we have the Truma 6E boiler with blown air heating.

The heating doesn't seem very hot, the boiler fires up okay and seems to work okay but after a few minutes I can hear it turn off, as if it's up to temp. But on our previous Hymer T class the heating came on and the air from the vents was quite a flow, van got very warm before the Truma switched itself off.

On this one the air from the vents seems fairly warm but not much power behind it, more like gentle breeze than a hot air drier. The boiler is also very quiet, as in we can hardly hear it.

Is there any way to increase the air flow ? Could it be the temp sensor over the door ?

 

[MikeD]

If you are EHU only it has a reduced power. I think by memory around 2kw.

Run it on gas to get the place warm and then switch back.

 

[Boringfrog]

Yeah, are you using E or G?

 

[Lenny HB]

Just turn the fan speed up to high. I've found only need to do that when its blowing a gale in the winter.

 

[paddymcc]

Is the thermostat turned down? On ours (2006 hymer) it is the dial on the heater switch.

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[KUSKUS]

Could be a faulty thermostat, cheap to replace and five minute job to fit.

 

[BusyBuilder]

Run either on gas or both gas or electric, no real difference, we only have the 2 dials so no option to increase the fan. Even with the temp set at 5 (highest) it does get warm but no where near like previous van.

Where can I get a new thermostat ? does it just pop off the fascia it's fixed to
above the door ?

 

[walburga]

Are all the heating ducts attached to the truma? One of ours had come adrift...they only appear to be a push-on fit!

 

[dave newell]

We recently fixed a Combi with a similar issue, it lit and ran fine for water heating but gave little output on space heating. Turned out to be the distribution fan controller on the pcb playing up, new pcb fixed it. If you can get at the heater and see if the distribution fan is running will give you a clue, on the one we had in the fan was running very slowly and only in fits and starts.

D.

 

[MotorhomeMart]

Could be a faulty thermostat, cheap to replace and five minute job to fit.

Do you mean the black button type thermostat? My heating will permanently run on the highest fan and heating sensor. I am thinking it may be the thermostat.

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[Boringfrog]

Do you mean the black button type thermostat? My heating will permanently run on the highest fan and heating sensor. I am thinking it may be the thermostat.

Hope he's fixed this, as it was last December. ?

 

[MotorhomeMart]

Hope he's fixed this, as it was last December. ?

I hope so too. However I was searching the threads as I too have a problem. I think it is probably the room temperature sensor which I hope is easy to replace.

 

[Boringfrog]

I hope so too. However I was searching the threads as I too have a problem. I think it is probably the room temperature sensor which I hope is easy to replace.

I had a similar problem and bought a new thermistor, I disconnected the old one from boiler side and the heating ran at full heat, reconnected and all was working again.

 

[ukdw]

I have a Truma Combi 4e with possibly a similar problem.

Heat comes out - but only fairly slowly when on electricity. Not too bad and it does eventually heat up the van - a 2010 Autocruise Alto. The main problem I have is that after about an hour the heat stops coming out. The lights on the two duals stay on. If I turn off the heating and leave it for a few minutes then turn it back on heat starts coming out again (at the same fairly slow speed),

Is this normal - or are you meant to be able to leave the heating on all day - with it turning off and on based on the temperature sensor?

 

[tonyidle]

You can prove whether the sensor is faulty: if you disconnect it the heating thinks the van is permanently cold and should run flat out continuously. If you short-circuit it the heating thinks the van is permanently up to temperature and the heating will never come on. The sensor is a NTC thermistor.

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[ukdw]

Ok Tony thanks, will try short circuiting it to see if that keeps it on permanently.

 

[David and Sally]

Ok Tony thanks, will try short circuiting it to see if that keeps it on permanently.

No, leave open circuit?

 

[MikeD]

I have a Truma Combi 4e with possibly a similar problem.

Heat comes out - but only fairly slowly when on electricity. Not too bad and it does eventually heat up the van - a 2010 Autocruise Alto. The main problem I have is that after about an hour the heat stops coming out. The lights on the two duals stay on. If I turn off the heating and leave it for a few minutes then turn it back on heat starts coming out again (at the same fairly slow speed),

Is this normal - or are you meant to be able to leave the heating on all day - with it turning off and on based on the temperature sensor?

I can't remember the actual numbers but I think on the 240v electric the Truma is only running at 2kW. You need both Gas and electric to get it to operate at the full 4kW.

I find on our van that we need to warm the van using both electric and gas and then just 240v EHU to keep the temperature/van warm.

Our Truma fan speeds up considerably when the gas is running with 240v EHU.

 

[ukdw]

Ok thanks both - will try disconnecting the temperature sensor first to see if the heating stays on permanently. Will also see if fan runs faster on gas/electric - never actually tried this combination as too mean to turn on gas when I am on EHU

 

[Brian S]

Hi all
I have moved to the Truma Combi in my new tracker and I can tell you that with no fault in the hard ware you are not going to improve this problem . My MOHO has been to Don Amott for a week and they do not accept there’s a problem . . And I was told that if I did not with to use the boost button for water I should use gas .
I was also told by a member of staff that when on electric they set the temperature 2 degrees higher
The MOHO has also had a well at Truma on the A50 . There engineer confidently told me that when I returned to pick up the unit I would see that on electric I would see the room temperature archived and 9 lites of 60degree water within a cooler of hours
Sadly this was not achieved and once again I was told if I did not wish to do manual intervention use Gas ( where is the green policy that we should all be moving towards)
Let me clearly explain why this this Truma Combi fails to reach room temperature and therefore not switch to water heating mode
Point 1 the firmware prioritises heating
Point 2 if gas Is selected the burner has the option to burn at 6 kw (6e model ) 4kw 2kw
Point 3 in mix2 mode the heating does the following 6kw gas when 10degress of target temp 4kw gas as it gets closer to target 1800watts electric
And shock horror when it’s 1.5 degrees of the target 900watts (even if you have selected ELEC 2 ) I can tell that 900watts with an outside temp lower than 10 degrees will not heat up a 7.5 meter MOHO
the reason gas works Is gas minimum energy is 2000watts
And Electric is 900watts
1100watts difference
If you wish to prove this wait until the amps displayed on most control panels drops to a nominal 1kw and place a small 1kw heater safely in the MOHO in the case of mine within 20 mins the room temp was archived and a full tank of hot water at 60degrees
Truma need to change the firmware to allow 1800watts when we the customers select it as I says in the manual
Thanks for reading Brian

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[dunnah01]

I s

Hi all
I have moved to the Truma Combi in my new tracker and I can tell you that with no fault in the hard ware you are not going to improve this problem . My MOHO has been to Don Amott for a week and they do not accept there’s a problem . . And I was told that if I did not with to use the boost button for water I should use gas .
I was also told by a member of staff that when on electric they set the temperature 2 degrees higher
The MOHO has also had a well at Truma on the A50 . There engineer confidently told me that when I returned to pick up the unit I would see that on electric I would see the room temperature archived and 9 lites of 60degree water within a cooler of hours
Sadly this was not achieved and once again I was told if I did not wish to do manual intervention use Gas ( where is the green policy that we should all be moving towards)
Let me clearly explain why this this Truma Combi fails to reach room temperature and therefore not switch to water heating mode
Point 1 the firmware prioritises heating
Point 2 if gas Is selected the burner has the option to burn at 6 kw (6e model ) 4kw 2kw
Point 3 in mix2 mode the heating does the following 6kw gas when 10degress of target temp 4kw gas as it gets closer to target 1800watts electric
And shock horror when it’s 1.5 degrees of the target 900watts (even if you have selected ELEC 2 ) I can tell that 900watts with an outside temp lower than 10 degrees will not heat up a 7.5 meter MOHO
the reason gas works Is gas minimum energy is 2000watts
And Electric is 900watts
1100watts difference
If you wish to prove this wait until the amps displayed on most control panels drops to a nominal 1kw and place a small 1kw heater safely in the MOHO in the case of mine within 20 mins the room temp was archived and a full tank of hot water at 60degrees
Truma need to change the firmware to allow 1800watts when we the customers select it as I says in the manual
Thanks for reading Brian

I suspect Truma have to play it safe on EHU to limit power to ensure it works on the lowest supply which can be around 3 amps.
You'll just have to wait longer for it to warm up I'm afraid - or give it a gas blast to turbo it.

 

[Lenny HB]

Mine is gas only so don't get those sort of problems, I don't think it's worth the extra cost of the electric option so I've never bothered with it on any of our vans.

 

[dunnah01]

Mine is gas only so don't get those sort of problems, I don't think it's worth the extra cost of the electric option so I've never bothered with it on any of our vans.

Elec option is great on an inclusive elecky site in winter but agree, not much use otherwise

 

[Lenny HB]

Elec option is great on an inclusive elecky site in winter but agree, not much use otherwise

Rarely use sites or EHU.

 

[Brian S]

Re comment Truma have to limit 3amps
This is why Truma give you and me the option to select 4amps or 8amps
The point being that on elec2 and on gas2 it has draw 8amps until it gets to 1.5 degress of target and reduces to 4amps due to the firmware
And as for the point I will have to wait longer . I have tried that and 48 hrs later set temperature has not been achieved and I only have 4litres of Luke warm water .
That's a long time once again Truma need to allow 1800watts to be available
Thanks for the interest Brian

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[dunnah01]

Re comment Truma have to limit 3amps
This is why Truma give you and me the option to select 4amps or 8amps
The point being that on elec2 and on gas2 it has draw 8amps until it gets to 1.5 degress of target and reduces to 4amps due to the firmware
And as for the point I will have to wait longer . I have tried that and 48 hrs later set temperature has not been achieved and I only have 4litres of Luke warm water .
That's a long time once again Truma need to allow 1800watts to be available
Thanks for the interest Brian

Never looked to closely at the system tbh. I have one or two squiggles with no mention of what current they represent. No problems through last winter with heating and hot water on just EHU when frozen outside although it was left on about No. 3, 60° and 2 squiggles most of the time so maybe they changed the firmware after my 2010 model

 

[Brian S]

You may be luck that your on the older system and not the new one with screen .it sounds like the new one is a step backwards

 

[Compactliner]

having had both systems, I'd say the CP plus was a far better than the older system in many respects, the most significant is that the fan speed is user controllable (eco or high) meaning low power options can be run with high fan or has can be great with just the eco setting....whereas the previous set up had the fan speed based on the amount of heat available at the boiler....so low outputs (electric) usually generated low fan speeds and therefore poor distribution.

 

[DandG5515]

Hi seen some very complicated answers to this, all I can say my 6g does not always switch from low to high speed dispute leaving it on in max. I have two ways to overcome this, switch it off and switch it back on 15 secs later, or shut the vents near the boiler for a minute forcing temperature up in boiler and then boiler kicks in to high speed. Lived with it like that for 5 years. Always behaves itself when serviced.

 

[ukdw]

No, leave open circuit?

Dave and Sally, sorry for the long delay in responding, wife wouldn't let me muck about with heating while we were dependent on van last year.

Same problem still occurring, tested on gas only so far. Heating works ok to start with then turns off after a while. Tried disconnecting the sensor and it seems to turn the heating off, rather than leaving it on. Also tried connecting the two wires together and heating also doesn't come on.

The only time the heating comes on is when the sensor is connected.

any ideas or do I need to get an engineer to look at it?

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