Carver 1800 won't stay lit

[Octobox]

Hi all i have converted my own van and installed a carver 1800 manual ignition heater.
I am having trouble with it staying alight. I have modified the exhaust to exit the side of the van with a vent to stop wind. I have also modified the inlet to stop the wind blowing it out. I can now hold an airline across the exhaust and inlet with little affect to the flame. I have also cleaned out the gas trumpets with the mesh on top. I have taken appart the gas valve and cleaned thoroughly although it didn't realy need cleaning it was immaculate. I can't see the problem being the thermocouple as the flame goes out then about 20 seconds later it loses power and then drops the gas valve, you can hear a very obvious click well after the flame has died. Also the wax regulator seems to work well as it self regulates nicley. It will somtimes run all night but other times it just goes out. I am running propane and everything else seems to work fine. I have also blown all the lines out with compressed air to remove any moisture that might of been freezing up. I have also tried gas straight to the heater avoiding the manifold and line with no differance.

Any advice would be much appreciated

 

[ProfJohnL]

Hi all i have converted my own van and installed a carver 1800 manual ignition heater.
I am having trouble with it staying alight. I have modified the exhaust to exit the side of the van with a vent to stop wind. I have also modified the inlet to stop the wind blowing it out. I can now hold an airline across the exhaust and inlet with little affect to the flame. I have also cleaned out the gas trumpets with the mesh on top. I have taken appart the gas valve and cleaned thoroughly although it didn't realy need cleaning it was immaculate. I can't see the problem being the thermocouple as the flame goes out then about 20 seconds later it loses power and then drops the gas valve, you can hear a very obvious click well after the flame has died. Also the wax regulator seems to work well as it self regulates nicley. It will somtimes run all night but other times it just goes out. I am running propane and everything else seems to work fine. I have also blown all the lines out with compressed air to remove any moisture that might of been freezing up. I have also tried gas straight to the heater avoiding the manifold and line with no differance.

Any advice would be much appreciated

Hello Octobox

DO NOT ATTEMPT TO USE YOUR HEATER UNTIL IT HAS BEEN FITTED IN ACCORDANCE WITH THE MANUFACTURERS INSTRUCTIONS

First and foremost both the Truma and Carver 1800 series models of convector heaters are specifically designed for through the floor installation, It is a finely "balanced flue" design and the under floor parts must not be baffled or boxed in as it will disrupt the heaters ability to segregate exhaust gasses from air intake gasses.

It is highly likely the baffles or box you have created will cause the heater to be affected by wind and it is highly likely the problem you are experiencing is the heater ingesting its own flue products, or there is an adverse pressure differential across the exhaust and air intake which is countering the appliance's thermal drive and preventing fresh air getting to the burner and snuffing out the flame.

You have made an unauthorised modification to the installation which is counter to the manufacturers specific fitting instructions and as such the appliance must not be used.

Because the appliance has an automatic flame failure detection system that will shut the gas off if the flame goes out, it is unlikely to be a danger to anyone, but neither will it work correctly.

 

[gary]

Right or wrong, not sure about the intake/exhaust mods being the whole problem, they not sounding too different from the boat conversion kit, or Carvers over jetted 1800 the Carver 3000SBD which was roof flued. However my worry would be taking 'the valve to bits to clean', not only whether correct lubricant or amount used?, but their calibrated and in my experience not easy to get back together so they work correctly.
As the prof says then, you really need full understanding before attempting any modifications, getting it wrong kills!

 

[ProfJohnL]

Hello Gary

The OP's actions are contrary to gas regulations becasue he has modified a gas appliance and installed in a non approved or tested manner. Irrespective of any dispensations for touring caravans.

Without seeing the specifics of the modifications no one can be certain that the mods have not affected the safety of the appliance, but on the basis it has only been boxed in, it would still mean the FFD system should still prevent unburnt gas escapes.

Interference with the flue or air intake systems and clearances may have a range of effects and most certainly could cause incomplete combustion raising soot and other gaseous emissions beyond legally permitted levels for gas appliances in the UK. Under some conditions it might cause the appliance to self extinguish either due to back pressure caused by windage, or the baking up of flue products through the exchanger stiffing fresh air to the burner.

The 1800 heaters were often fitted close to the caravan wheels or other obstruction under the caravan, and many fitters will know that it was important to to take account of these when deciding where to fit the appliance. Where such care had not been exercised, there were many examples where the appliance would sometimes loose its flame and shut down. Usually rotating the air intake was sufficient to prevent windage problems, but that would not be an option where the the underfloor section has been closed in on 3 sides and the bottom.

Any gas fitter would be required to disconnect and seal the appliance and pipework and to issue "do not use notice" for the appliance as it is not fitted in accordance with the manufacturers instructions.

The Boat models needed special castings, and purging systems, and other bits and pieces. I had forgotten the 3000SBD, but in that case the the overwintering needed the roof flue to enable the heater to create the correct thermal draw on the flue.

 

[Octobox]

Ok I appreciate your concerns that i am going to gas myself. I have used the exact same twin wall pipe of an roof vented model. The pipe is a perfect fit to the burner with new seal. The pipe is about 2 foot long till it exits the side of the van in a manor very similar to a roof vent with no restrictions or baffels. Like i said in my first post it will sometimes run all night with no worries and other times it's flame just dies like it is out of gas but it isn’t. Is there a was of posting some picks so i can explain the mods a little clearer.

Cheers for the replies

 

[ProfJohnL]

You clearly have not taken heed of my warning or advice.

The Carver 1800 is not designed to be used in the manner you have described, no amount of pictures will change that fact. Yet alone that you have actually committed a criminal offence by unlawfully dismantling and modifying a gas appliance or installing it in a an unapproved manner.

IT IS THAT SERIOUS.

I am not surprised the heater is temperamental, but I am certainly not going to advise you on how it may be remedied beyond having professionally reinstalled correctly and tested.

As a gas engineer (even retired) I have to comply with the regulations and give you that advise.