Biasi Riva Advance Y Plan Room & Cylinder Stats Problem has been intermittently present for some time it would seem. When I first fired the system up yesterday evening (not a new install just replaced the 3 port valve for another reason) the system worked & came up to temp through the hot water circuit then switched to heating & the boiler came up to temp but the water is hot on the flow side of the boiler but cool on the return, even with just the hot water circuit on now. I reckon there must either be a blockage somewhere or something is shut on the boiler to stop the flow. The pump works, the flow pipe is hot, the boiler fires up to temp but doesn't flow through so shuts down Any ideas? Telephoned a local plumber but he's on holiday until Tuesday & it's bloody freezing! Hope someone can help or at least give me something to check Thanks:
Just fired it up & it worked for about 10 mins then the burners shut down, there's a lot of clicking & whirring from the motor on top of the diverter valve. Could it be that that's faulty, what would be the outcome if the motor was not working correctly, is there any way of testing it? Thanks
Diverter valve, or more likely blocked heat exchanger I would think, I would try some Sentinenel X800 in the system for a few days. How old is boiler.
You say you replaced the diverter valve? With a complete new unit - both valve section and motorhead. It shouldn't be 'clicking and whirring' for any length of time - when you call for CH, it should move smoothly to that position within a few short seconds, go 'click' and the boiler & pump should fire up right away. Ditto with DHW. And right in t'middle when both on. Get someone to operate your timer - turn on CH for 30 seconds. Turn it off. Turn on DHW for ditto. Obviously if the cylinder temp is at that set on its thermostat, then the 3-port valve will not react when the timer calls for DHW. Ditto for the room stat and CH. Ok, when the valve moves accrediting to command and the boiler fires up, put your hand on the flow pipe to the valve and then check how well it continues to heat up beyond the valve. If the flow pipe to the valve heats up to hand-hot in a few seconds, then it should ditto beyond the valve in whatever direction the valve has opened. I still suspect the 3-port valve is the issue, because you say it does work at times, so I wouldn't expect a pipe blockage to be intermittent like that - a blockage would be a blockage is a blockage.
Thanks for the reply. Sorry I haven't made this clear, I replaced the mid position valve but it's the diverter valve in the boiler that's clicking & whirring - like it's trying to connect but not managing, almost like a microswitch clicking in & out. It's not the flow micro switch on the front of the valve though. The mid position valve is working fine now Boiler is about 5-6yrs old, yes I'm coming to the same conclusion that it's unlikely to be a blockage. It fired up this morning no problem at all.............for 10 mins then the motor on top of the diverter valve in the boiler started clicking & whirring & the flow stopped. Boiler temp stayed fairly high but I guess as it wasn't flowing through it wasn't igniting the burners. I will fit a filter soon yes
Which could be the diverter valve or could be a block heat exchanger restricting flow & causing boiler to shut down.
If I remove the motor head on the diverter valve will that prove either? Boiler hasn't been noisy & I had to drain the system last year to add a rad - the water wasn't that bad at all & I've always had X200 in the system & replaced last year.
What make and model and TYPE of boiler is this, Junks? If it has a diverter valve inside it, surely that makes it a combi boiler? In which case it wouldn't have a 3-port valve outside it. I'm confused...
If you replaced the 3-port valve and it now works smoothly as I described in post #4, then I think you can assume it's working chust fine. What I would like to know is, what's this thing inside your boiler that goes clickety click? Can you post a photo? Make it under 2MP.
Sorry again! When it was fitted it was plumbed up (by a professional not me!!) to not use the instant water heating & use a hot water cylinder as per a normal Y plan system. The timer & the hot water temp control isn't used
I'm really confused... http://www.biasi.co.uk/assets/publi...ce ISO (B) Combi_User Installation Manual.pdf Page 11 gives the settings for two options - CH and DHW outputs, or DHW only. It doesn't seem to provide for a CH only - which could then be 3-ported for DHW and CH as yours seemingly does. Unless I'm missing something. In any case, as a non-pro, this issue is waaay over my head
Yep, that's what I was gathering from your description. Only -from what I understand - that option is not described in the instructions I've linked to. Why on earth didn't he install a normal 'system' boiler and be done?! If I were you, I'd call up Biasi and ask them if the way your system is connected is ok - and, if so, then ask if the symptoms you are experiencing suggests anything obvious. (If the diverter vale inside the boiler is clicking away, that is where I'd be focussing my attention. Whether it's faulty, or whether it's having a fit because it's not meant to be fitted this way. Are you sure the controls on the front of the boiler haven't been touched recently - you haven't turned up the DHW control?
Now that is very intresting, & I'm asking myself as to why it was done that way. Prehap one of our plumbers can answer that.
I've no idea! He just said I'll connect it like this but has been working for 6-7 yrs so I guess it's ok
Good photo! I cannot see all the pipes going to that item, but it does look like the diverter valve right enough. See my earlier post - I think you should call Biasi. (Also check you haven't touched the DHC controls on the front panel).
Again I've no idea sadly bu it has been working fine (other than the problems with the boiler under warranty & a couple since).
Forums
Facebook
Twitter
You Tube
Instagram
Shop