Ravenheat LS80 no DHW, thermistor and diaphramn changed

[Agile]

OK

With all that I must conclude that you have a failed diverter valve ( or just possibly an out of tolerance switch but thats unlikely ).

AND

a blocked plate heat exchanger!


To check the former you would need an inspection mirror and a fibre optic torch to visually inspect the shaft in the diverter valve. However, in most cases the valve has failed so hardly worth the bother if you are not an engineer who goes to this make often.

Tony

 

[ollski]

Just whip the diverter out and change the diaphragm!

 

[oilhead]

Is the pump working?

 

[Mickymoody]

Sorry for not getting back; the diaphramn has now been changed, the old old was split and broken, but still no hot water. More money down the drain! Me and boilers don't have much luck.

 

[Andygasman2010]

So... Heating works fine, but when you turn on a tap NOTHING happens?

If that's correct, make access to the PCB and look for connector CN4 where at the end should be two wires, green and black. Link these two together and see if the boiler fires. It's the DHW flow switch. Doing this will miss-out the DHW diaphragm/microswitch and wiring. (make sure you run a hot tap when you do this, incase it does fire up)

Post back results

 

[Mickymoody]

When DHW flow switch is bypassed, boiler fires. Radiators get warm. Tap stays cold.

Before diaphramn was replaced running hot water in this mode made pressure go down accordingly. Pressure seems to hold at present.

 

[Andygasman2010]

If you leave the tap off and bypass the switch, do the rads get hot?

 

[Mickymoody]

iirc steam was vented outside, and the gas fail light came on, and the boiler made terrible noises. And the pressure gauge went to 1/2 bar to 4 bar randomly, with gushing noises, as I posted above.

But the overheat trip didn't occur. And the rads didn't get hot, as the boiler was tripped.

Just looked now, and the pressure does seem to be dropping slowly.

 

[Andygasman2010]

When DHW flow switch is bypassed, boiler fires. Radiators get warm. Tap stays cold.

Before diaphramn was replaced running hot water in this mode made pressure go down accordingly. Pressure seems to hold at present.

This tells me that the diverter valve is passing (assuming you had the tap running) i wouldn't pay much attention to the pressure fluctuation.

So If you run a hot tap, will the burner fire of it's own accord? Without you bypassing the switch?

 

[Mickymoody]

When DHW flow switch is bypassed, boiler fires. Radiators get warm. Tap stays cold.

Before diaphramn was replaced running hot water in this mode made pressure go down accordingly. Pressure seems to hold at present.

This tells me that the diverter valve is passing. i wouldn't pay much attention to the pressure fluctuation.

So If you run a hot tap, will the burner fire of it's own accord? Without you bypassing the switch?

The old diaphramn was properly melted/holed, rather than a simple fail. I turn the tap on, and the boiler does not fire.

It tells you that the divertor valve is passing...what does that tell me, in English? lol

 

[Andygasman2010]

haha i'm affraid it is english, sorry if it's too technical to understand. some of the things you're describing are a little conflicting, maybe it's time to get an RGI in to look at the problem

so with the new diaphragm, when turning on a hot tap can you see the pin come out and make that switch??

 

[Mickymoody]

haha i'm affraid it is english, sorry if it's too technical to understand. some of the things you're describing are a little conflicting, maybe it's time to get an RGI in to look at the problem

so with the new diaphragm, when turning on a hot tap can you see the pin come out and make that switch??

There have been that many tests run on this that they are now conflicting as to what has been tested etc...I've had a RGI in to look at it, that replaced the diaphramn, and they have no clue as to what is the next stage.

Can't see any switch near the diaphramn side, but the flow switch is switching on selected DHW.

I'm a computer engineer -divertor valve is passing means nothing to me. I don't post unusual terms for computer repairs that people don't understand.

To recap, CH works, DHW doesn't. During the fail, the overheat trip failed, when using the HW. Then HW failed. The thermistor for DHW was changed, no change, the diaphram was changed, that was busted, still no go. The only switch near the 3 way divertor valve is the flow switch for the CH, and that fires the boiler regardless of tap water flow.

So divertor valve is passing..means what? The diaphramn has been replaced.

Currently, I've had 4 different CH engineers to fix 2 different boilers, and one broke the origional, by fitting a 3A fuse, where a 315mA fuse was required, parts replaced, and no go in my old boiler, and currently 2 parts fitted to my new boiler, and both have failed to resolve the problem.

So understandbly upset. I suspect that you refer to the 3 way divertor valve @ £122 is faulty also. It seems that adding a diaphramn wasn't enough, due to the break up of the rubber material on the diaphramn..an obvious fault.

So if you ask a computer tech answer, I answer straight. But don't change my mind, as a suck it and see solution.

IF the flow switch worked, kicked in when HW selected, then it would work surely?

But flow switch is for DHW only, as when turning the tap on, nothing happens..

A faulty diaphramn has been replaced, and the thermistor..thats stood me to over £50 and still no working boiler. And that excludes time worked.

If I worked like that in my trade, I'd be sacked quickly.

Can someone answer the straighforward question; why does it not work?

 

[Agile]

I'm a computer engineer -divertor valve is passing means nothing to me. I don't post unusual terms for computer repairs that people don't understand.

Perhaps you dont but most others do.

"Download new drivers" Doesn't tell me if to "run" or "save" or where to put them?

Proper old Windows enabled ME to shoose when to put anything that I downloaded. Vista seems to choose to put them into a "downloads" file but Vista does not look for drivers in a download file.

Vista does not allow me to set a printer up on a USB virtual printer port "because it looks for anything on a USB port and finds it automatically". But it does not find my printer!!!

Vista assumes that I know nothing about computers but when Vista does not work properly I cannot do anything myself. Totaly................

Within minutes I could fix your boiler if I was there. But I cannot wade through 27 posts and extract salient data.

As far as I can guess when the demand awitch has been made to actuate its responding as if it has a totally blocked plate HE. That should have been checked/cleaned while the diverter valve was out.

Tony

 

[Mickymoody]

I'm a computer engineer -divertor valve is passing means nothing to me. I don't post unusual terms for computer repairs that people don't understand.

Perhaps you dont but most others do.

"Download new drivers" Doesn't tell me if to "run" or "save" or where to put them?

Proper old Windows enabled ME to shoose when to put anything that I downloaded. Vista seems to choose to put them into a "downloads" file but Vista does not look for drivers in a download file.

Vista does not allow me to set a printer up on a USB virtual printer port "because it looks for anything on a USB port and finds it automatically". But it does not find my printer!!!

Vista assumes that I know nothing about computers but when Vista does not work properly I cannot do anything myself. Totaly................

Within minutes I could fix your boiler if I was there. But I cannot wade through 27 posts and extract salient data.

As far as I can guess when the demand awitch has been made to actuate its responding as if it has a totally blocked plate HE. That should have been checked/cleaned while the diverter valve was out.

Tony

But as stated; I seem to have recruited the worst engineers ever. I'm no boiler engineer..what I write is my observations..But - Agile..never use Vista, it's the worst OS ever, use XP or Win7. So many tests have been carried out now..that they blend into one. melted diaphramn, possible thermistor fault, but no answers.

Guess that a demand switch regarding a divertor plate? Explain?

 

[Agile]

I bought the computer when Vista was the latest and tagged as the ultimate operating system! it came with the machine.

Within several months, computers were coming with Vista but you could pay EXTRA to UPGRADE to XP which is an earlier system!

At least my new notebook has XP but whilst it logs on to the WiFi router it does not access the internet through the AOL (talktalk) ISP.

So I have ended up with the worst OS and the worst ISP and a notebook with the best OS but unable to contact the internet!

But at least I still have my AOL screen names for the last 25 years whilst all my friends/colleagues have been through ISPs that failed after 1-2 years and they dont keep the same email for more than a few years at the most. I have Agile Services, Agile Sales and Tony Glazier ! I have also an early 121 phone number 07956 440480 as well as a similar BT landline xxx 4080, another landline xxx 9999 and an 0800 018 8008

The plate HE is the plate heat exchanger and is the butter pack sized stainless bit behind the diverter valve which seems blocked in your case. I probably said that in posts 5-15 somewhere.

Tony