No water flowing through Truma boiler to HW taps help !

4wheelen

Hello folks, just new here. I have recently bought a 95 Hymer 564 which we are delighted with, but are encountering a few niggly teething problems. 2 things are causing me concern regarding the heating and hot water. First problem is the heating is not working on the Truma 3400, I can put up with this for a while until I sort out the bigger problem i.e the cold water is not able to flow through the boiler and reach any of the hot water taps. 12v supply is on, hot taps are open, fresh water tank is full and pump is working (no problem pumping water to cold water taps). I have disconnected the water feed pipe from the frost protection valve and it is flowing through ok but will not seem to pass through the cold feed (bottom) inlet into the boiler I have tried blowing into it also but it seems totally blocked ( I have also left hot taps open and pump on for up to 20 mins to allow boiler to fill). I am wondering is this caused by scaling/furring of the boiler. I am also not sure if the fact that there is no water in the boiler prevents the heating from coming on as a safety device to prevent damage to the boiler. Anyone got any ideas on why this might be happening ??

sunchaser

Have a look at this site.
www.motorhomefacts.com/ftopicp-450710.html

Aidan_M_M

that heater shouldn't be operated without water . And it sounds like you have a blockage alright . Did you take off the top hose connection and see if that makes any difference?

4wheelen

sunchaser wrote: »

Have a look at this site.
www.motorhomefacts.com/ftopicp-450710.html

Aidan_M_M wrote: »

that heater shouldn't be operated without water . And it sounds like you have a blockage alright . Did you take off the top hose connection and see if that makes any difference?

Thanks Fellas, made some progress today, took the bottom inlet hose off the boiler today and initially nothing coming out, tried a couple of lung bursting blows through it with little effect and disconnected top outlet from the boiler as well, eventually a drip from the bottom inlet developed into several drips, many more lung bursting blows eventually a splurge of total gunge came back through inlet, kept going with the process and water + filthty gunge flow increased. Every time i blew through inlet pipe it seemed to dislodge more gunge, water eventually turned cleaner with less dirt, I could also hear hissing of 'clear' breather inlet at top which I took to be a good omen. By the end of the draining I had filled the kitchen sink about 1 1/2 times which I estimated would have been about 10 litres or so. I then reconnected the cold water supply pipe to the boiler inlet opened all the hot taps and turned on the 12v supply and after much hissing and spitting - Success water finally flowing through all hot taps and shower head. I decided to open the dump/frost valve to clean out boiler and did this empty/refill process about 4 times until I was content that the water coming out the dump valve was totally clean. Judging by the junk in there and the difficulty in clearing it I have come to the conclusion that it has been that way for some time, my only consolation from this is that if the heater was running then at least the boiler was fairly full of water. I will try and post a few pics of what came out of the boiler, it was like a brown sandy/silt fluid with blue-ish/green flecks through it which I think was stained copper or paint flecks, either way it did'nt taste to good at the time, I'll have to sterilize with alcohol later
Needless to say the heater did'nt work after all that. Fan comes on ignition process happens and then shuts down, red and amber light along with green. Any help or advice with this would be much appreciated.

Aidan_M_M

that blue green is paint from the inside of the water jacket , Not a good sign , it only comes off when the internals start corroding . New tanks cannot be sourcd for those , only s/h ones which are like hen's teeth . Truma prefer to sell you a new Combi unit for about 2k....

4wheelen

Thanks Aiden, how can truma justify 2K for that ???, I can buy an energy efficient condensing boiler capable of heating a 4 bed house including an external galvanised housing unit and electrics for 1K, plumbed and wired for £500 max.