ravenheat csi 85 c. heating prob.

[Homesafe]

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hello everyone, this combi is working fine in dhw mode but in c. heating it comes on for a while and then goes to lock out,

i have an idea it may be the limit stat. but someone may know better,

at the moment have put some cleaner in the system and will order the stat. tommorow, apparently you can only get them from ravenheat.

and if anyone has MI,s for this boiler i,d like a copy please,

any positive input welcome

 

[gas4you]

I thought these MI's were available as pdf on the Ravenheat website

Any parts supplier can get these parts.

I either use my local independent or parts center, whoever is quicker and/or cheaper

 

[Homesafe]

hi g4you, your right its on the website,

lady at parts centre said she couldnt find the clip on type on there list and would have to order it from ravenhaet direct, they also have have to order it from ravenheat cos its not a regular part or something

i think abcot do one at 4.50 or sumink will give them ring tmrw,

what do you think of my diagnosis ,
think slugbaby recomends changing this for the above problem also

 

[homes]

it is always a good way to go with a cheap part like ch.thermistor they cost about £16 +vat . have you checked resistance?

 

[Agile]

what do you think of my diagnosis ,

Even at this hour I think that you will find that its the fan PCB failed!

But then I did not get up until after the Archers and only went to three boilers as today is a day of rest.

Tony

 

[Homesafe]

day of rest, your an animal tony
the fan pcb you say , then why is it working on hot water as it should?

 

[gas4you]

If it was the fan modulating board, I would have expected it to keep start/stopping quickly when on ch, not 'goes off after a while'.

Is your description accurate?

 

[Agile]

Goes off after a while is exactly what I would have expected !

Tony

 

[Homesafe]

it goes to overheat on CH and not in DHW, the red light comes on flashing about once a second and needing manual reset.

and it does this after half hour or so,

then when it cools down it can be reset and it will go on again for half hour.

 

[Agile]

Are you quite sure that its really overheating?

If it were than I would be suspecting the CH temp sensor ( probably 25k cold )

However the fan PCB fault causes the fan to fail to run at slow speeds. The effect is therefore failure when the CH is up to temperature and the boiler tries to modulate back.

The same problem is still present on DHW but the normally greater heat demand usually makes it never happen.

Perhaps if you set a minimum DHW flow rate and minimum DHW temperature you might be able to get it to fail if its the fan PCB.

But you are the man on site!

Tony

 

[Homesafe]

can i check BP with gauge to see if it modulates and rule out the modulation probs.

ie.see if it does modulate then that would rule out slow fan ,wouldnt it?

i have already checked once and am sure it modulated down after going to max BP.

 

[Agile]

I dont think you can do anything useful like that.

You need to know if its overheating as you said or going to lockout as a result of the fan PCB fault.

I dont know what the boiler is doing, only you can see that.

Have you measured the CH temperature if you think its overheating?

Tony

 

[Homesafe]

I dont think you can do anything useful like that.

You need to know if its overheating as you said or going to lockout as a result of the fan PCB fault.

I dont know what the boiler is doing, only you can see that.

Have you measured the CH temperature if you think its overheating?

Tony

why do you not think i can do anything useful like that Tony?

i was just asking to confirm if modulation can be checked in such a method as checking BP

temp. on primary pipe was extremely high but i did not measure it sorry.

 

[Homesafe]

thanks to slugbaby and gas4you for helping

oh, and you TOny for your reply and trying,

but Its sorted know ,

buyakasha ,