Ravenheat Anti-Cycle

[jamiegleave]

Hi everyone

I have a Ravenheat Condensing Combi (CSI 120 Low Nox) which appears to be doing something rather strange. When the CH has not been on for a while (e.g. overnight) the timer / themostat kicks in as usual in the morning, and the boiler commences it fire up. The boiler runs for approximately 10 to 15 seconds, then it sounds like the fan slows down and then the boiler cuts out. Immediately following this, the 10 minute anti-cycle kicks in and the pump continues running. After the 10 mins is up, the boiler fires back up and the heating runs fine from then on in without any problems.

What is weird is that it only happens when the CH has not been on for several hours, presumably once the thing has cooled down (such as overnight) or if I turn the thermostat down during the daytime when I'm at work and come home and increase it in the evening.

No warning codes come on at the front panel. There is also no mention of this as a fault in the user manual. What I have noticed though is that once it has cut out, if I kill the power switch within that 10 min anti-cycle and then switch it back on, the system will immediately refire and will not cut out again. This has me perplexed somewhat. And it's not something that I can get someone out to demonstrate it to, as it only does this the once when cool!

JG

 

[gasmick2]

hi just read your post regarding your 120 ravenheat low nox boiler,
i have ask the tech dept about it during asking about another problem
on a job i was doing and he says that your problem is down to circulation problem from cold so the boiler is reaching 80deg in that short period of time so cutting off to go onto the anticycle mode of 10mins, he has recomended that the pump head is removed and checked for debris because when its cold it will be tighter and so cause the pump to run to slower and cause the lack of circulation

hope this helps mick

 

[jamiegleave]

Thanks Mick

One thing though - the problem persists if I have a shower prior to the heating coming on. If the pump is cold in the morning, then running the HW on the shower for 10 mins or so should get it working and warm it up prior to the heating coming on, yet after doing this it still cuts out after a few seconds of the heating kicking in.

Any thoughts?

Jamie

 

[Agile]

It does sound to me that it might be a PCB fault in the light of that last comment on shower use first.

The boiler should be under warrantee if it was correctly fitted by a CORGI installer.

If its dirt in the system then it might be a chargeable call.

Tony

 

[ddk]

possibly a PCB or NTC thermistor fault, hard to say, especially with a ravenheat

 

[jamiegleave]

Thanks guys

I understand that the thermistors can be an issue on Ravenheat's generally.

I noticed something else which may/may not be connected with this. The user manual states that this boiler will operate at a temperature of between 40 and 85 degrees on CH mode. On my boiler the digital display only shows this as going between min 45 degrees up to a max 74 degrees when the dial is turned to the maximum. Somewhat odd? Anyone experienced this with their 120 Low Nox?

Jamie

 

[gasmick2]

hi jamie well thats a different story now, and as you say 10 mins of using the hot water and i that works ok, i would have thought it was down to a heating sensor or it may be a pcb as Tony says but i would go for the sensor personally and if it is dirt in the system and its not been flushed out you will get charged i think its around £95
so if you have had it serviced according to the M I s then it should be covered under the 3 year warranty

bets of luck mick