Ravenheat Boiler Issues

[Happyunited]

Hello,

Happy new year to you.

Ravenheat CSI 85T Combi.

Before Xmas I had sme issues with my hot water, specifically the shower. The shower would start hot then after a minute would go cold then 20secs later hot again and repeat. I have been away Over Xmas so thought I'd sort it out in the new year. The problem is still there but only happens when the system is cold and the heating is off.

Then today the heating wouldn't come on as it usually would. With the heating set to on I could hear the pump turning but the boiler wouldn't ignite. I had a quick wiggle of some wires and plugs and when I wiggled the CH Sensor plug (see below) the boiler ignited. I assume this is the thermostat? So the boiler worked OK after this but then when it was due to come on later today the same thing happened and a quick wiggle made it work.

http://i1340.photobucket.com/albums...E-5136-4FD8-BFE0-E736440F11DB_zpsz4js1koo.jpg

Am I right in thinking i need to replace the CH Sensor? Would this also be related to the hot water problem or should I replace the DHW Sensor while I'm at it? I replaced the diverter value about a year ago and it's pushing the little pin out as it should so that's working.

I have a little 3month old baby in the house so any advice you can give is greatly appreciated.

Thank you

 

[andyroo1]

Hi,

I had the same problem, it turned out to be the pressure switch.

Took numerous visits though, and dozens of parts...

 

[Happyunited]

Hi,

I had the same problem, it turned out to be the pressure switch.

Took numerous visits though, and dozens of parts...

Hi, thanks for your quick reply.

Had you the water problem, the igniting problem or both?

What does the pressure switch do?

 

[andyroo1]

Both! The diverter was an issue at one stage too- when ebver we ran the hot tap the radiators heated up!
We have to have the heating on to get hot water.

And the shower you mention is all too familliar...

The pressure switch basically checks the fan is running before allowing the gas and ignition, if this is faulty / sticking it wont fire up.
(we went through a stage of tapping the side of the boiler (on advice from a professional lol) which somehow unstuck the switch sometimes in the short term - (basil fawlty eat your heart out!)

 

[Happyunited]

Both! The diverter was an issue at one stage too- when ebver we ran the hot tap the radiators heated up!
We have to have the heating on to get hot water.

And the shower you mention is all too familliar...

The pressure switch basically checks the fan is running before allowing the gas and ignition, if this is faulty / sticking it wont fire up.
(we went through a stage of tapping the side of the boiler (on advice from a professional lol) which somehow unstuck the switch sometimes in the short term - (basil fawlty eat your heart out!)

Thanks again.

Yes the old radiators heating up when the hot water was on. I'd people staying over in the summer and they were very concerned as to why I had he heating on when it was boiling outside! The diverter valve solved that problem.

I don't know much about the pressure switch but when I wiggle the green plug to the CH Sensor the boiler ignites or is this just coincidence?

 

[andyroo1]

I don't know much about the pressure switch but when I wiggle the green plug to the CH Sensor the boiler ignites or is this just coincidence?

Could be coincidence, or it could be corroded?, the plug just pulls off and a spanner unscrews the nut / sensor (but make sure you have de pressurised first / drained it or you will get very wet! This just tells the boiler's pcb "hey, its hot enough now, you can cut down the gas / shut it off"

 

[Happyunited]

I don't know much about the pressure switch but when I wiggle the green plug to the CH Sensor the boiler ignites or is this just coincidence?

Could be coincidence, or it could be corroded?, the plug just pulls off and a spanner unscrews the nut / sensor (but make sure you have de pressurised first / drained it or you will get very wet! This just tells the boiler's pcb "hey, its hot enough now, you can cut down the gas / shut it off"

And at £5 to replace it might be a good start. As mentioned before my heating control panel downstairs would usually shut off when it reaches the temperature I set it to but recently it has been going over and not shutting off hence we sitting there toasting (but wife and baby happy). Just had a look at that pressure switch, I take it it's behind the metal panel at the front?

Also do yo know if both the DHW and CH Sensor are both the same? They both look an easy fit - I can just drain the boiler using the red knob can't I? No need to drain the entire central heating system?

 

[Slugbabydotcom]

You can replace the CH sensor. This is a common problem.
Make sure the boiler is COLD before you do it. Trust me I learnt that one the hard way.

Andyroo is confusing the issue by telling you about a different problem which dates back to when honeywell changed APS production to China. Yes they did need a slap to get them working but as that is inside the combustion chamber. You shouldn't be going in there anyway.

If you touched the sensor and it worked then that is a good indication that you are on the right path.

The DHW sensor hardly ever goes wrong. I wouldn't bother changing it until you know it is faulty.

 

[andyroo1]

You shouldnt need to drain the whole system, just use the isolator valve.

The pressure switch will be at the top corner next to the fan and have some rubber pipes going to it- not sure if you would be able to do this one without a gas safe qualification though... i personally wouldnt risk it as it could potentially be unsafe.

Just be careful, and whatever you do dont try to access the combustion panel as you will need to be gas safe registered, its illegal otherwise.
And you cant be too careful with a baby in the house, if in doubt its better to get a qualified gas engineer to check it over.
I have cover on my boiler which includes an annual service & all call outs parts & labour for about £20 a month (which has been invaluable)

 

[Happyunited]

You can replace the CH sensor. This is a common problem.
Make sure the boiler is COLD before you do it. Trust me I learnt that one the hard way.

Andyroo is confusing the issue by telling you about a different problem which dates back to when honeywell changed APS production to China. Yes they did need a slap to get them working but as that is inside the combustion chamber you shouldn't be going in there anyway.

If you touched the sensor and it worked then that is a good indication that you are on the right path.

Thank you. So drain the boiler and have it cold - check.

Just north of the pipe where the ch sensor is is another part that has two plugs going into it, I gave this a wiggle and got an almighty shock!! Not sure what happened.

Do you think the CH sensor will solve my water problem too? Or will I change the DHW Sensor while I'm at it?

 

[andyroo1]

I would give this a read too
//www.diynot.com/forums/plumbing/diy-gas.8090/

 

[Happyunited]

I would give this a read too
//www.diynot.com/forums/plumbing/diy-gas.8090/

Thanks Andy. Baby or no baby I wouldn't be touching anything to do with Gas, it's simply not worth it.

 

[Slugbabydotcom]

Haha you don't need gas to do yourself in. Sounds like you just had a 240v blast of electricty. Let's be careful out there!

And yes just change the CH sensor. Theres less than 1/100 chance that the DHW one is gone as well. They hardly ever go.

 

[andyroo1]

Haha you don't need gas to do yourself in. Sounds like you just had a 240v blast of electricty. Let's be careful out there!

Sounds like you had a lucky escape happyunited (the fact your still typing!)

 

[Happyunited]

Haha you don't need gas to do yourself in. Sounds like you just had a 240v blast of electricty. Let's be careful out there!

And yes just change the CH sensor. Theres less than 1/100 chance that the DHW one is gone as well. They hardly ever go.

So the CH Sensor could be causing both my issues?

I was stupid not turning off the power but as far as I was aware I was only touching the the plastic plugs so not sure where the shock came from??

I had a quick lookon eBay but could only see the DHW sensors, need to have a better look, are they both the same?