Ravenheat RSF820/20 problem

[gavndee]

I have a Ravenheat RSF820/20 combi boiler fitted for the last 5 years. For the first 4, it has been faultless, but over the last year, there are one or two problems appearing.
First of all, the timer seems to alter itself, changing the on off times and days of it's own accord.
Secondly, when the unit is heating the radiators and you either call for dhw via the shower or the taps, it works fine, warming the water up nice and hot. However when the radiators are off, and dhw is called for, the water temprature doesn't heat up very much at all. I have also noticed that when this is happening, the radiators are heating up, even though they shouldn't be on. After reading through the manual, i understand that when the radiators are on and dhw is called for, the radiators should switch off while the taps call for water, not the other way around?
If anyone has any advice I would be very grateful.
thanks

 

[Rob]

The diverter valve is the cause for poor HW. Probably best to replace the whole unit if your confident. If not get some one in. Can be a bit tricky so ive heard.

Would check the spade connectors to clock, but could very well be the clock itslelf failing.

 

[gavndee]

thanks for that speedy reply. i'll look at getting the diverter valve replaced. looking at the clock now as we speak. does it have a battery? just a thought

 

[Rob]

Should have battery back up but should primarily be supplied from electic supply.

Any power cuts or reason for the load to be affected?

 

[gavndee]

no power cuts or disruptions to power supply. just had a look, and the timer works fine, but it doesn't always act up until after a day or so. so it's hard to find an intermittant fault.

 

[weareleeds]

Ravenheat clocks are like the rest of the boiler (not much good) i always put a remote timer next to boiler. Other fault is definetly diverter valve

 

[Slugbabydotcom]

Ravenheat clocks are like the rest of the boiler (not much good)

Ravenheat clock are made by graslin they just swap the terminal positions about.
I just wonder why Ravenheat and Ferroli seem to get the crap ones yet Baxi and other manufacturers tend to get the better ones

 

[gavndee]

thanks for the advice. just a couple of questions
is the diverter valve, the 3 way valve as it is called in the manual?
is it possible to do away with the timer and fit an aftermarket timer which will be more reliable than the ravenheat timer?
thanks again

 

[Rob]

thanks for the advice. just a couple of questions
is the diverter valve, the 3 way valve as it is called in the manual?
is it possible to do away with the timer and fit an aftermarket timer which will be more reliable than the ravenheat timer?
thanks again

yes and yes

 

[gavndee]

ok, just an update.
removed diverter valve from boiler and stripped it to find that the diaphram( is that spelled correctly?) has perished and has a hole in it.
ordered a new one from plumb centre and re fitted.
problem now sorted and house nice and warm again.
I removed the time clock and cleaned all the connections and gave them a hint of wd40 and it seems to have been ok so far, but then that fault seems to be intermittant so if it does carry on acting up i will replace it, it only takes a couple of mins to remove.
Thanks for all those who helped and advised, it's very much appreciated.

 

[Mr Lil]

I have a Ravenheat boiler and saw the timers online for sale...think they were £46 if it helps!