Tim Pearson Posted December 29, 2022 Author Share Posted December 29, 2022 Thx Kelvin, will keep it on the “to be followed up” list. T Link to comment Share on other sites More sharing options...
ProDave Posted December 29, 2022 Share Posted December 29, 2022 2 hours ago, Tim Pearson said: Ok so partially drained, filter removed (little or no debris), cleaned and reinserted. Flow switch is a Sika V3. Unclear which model at this stage, but label indicates 15l/min set point. Not yet removed to check paddle operation. Also, it may have an adjusting screw, tbc. Powered by cable back to control board - blue connector. Attached info. Any more suggestions before I remove FS, check paddle, any flow adjustment option? On electrical connection, what is there to check and how? thx again T Data sheet VK3 flow switch.pdf 355.39 kB · 1 download Ea3000_FlowSwitch operating instructions .pdf 1.7 MB · 1 download That's a different flow switch to mine. If no obvious issue, i would be tempted to buy the same switch head but with a lower flow rate to make it less fussy. Even if the flow rate is a bit on the low side it would trip on a different error if it was really an issue. Link to comment Share on other sites More sharing options...
Tim Pearson Posted December 29, 2022 Author Share Posted December 29, 2022 Help me out here Kelvin. Where would you expect the 2 way valve to be located? In the loft next to the buffer tank and DHW cylinder? Link to comment Share on other sites More sharing options...
ReedRichards Posted December 29, 2022 Share Posted December 29, 2022 Unless your plumber squandered copper pipes unnecessarily, there will be a single flow pipe from your ASHP to a two way valve that is close to (and probably about half way between) your buffer tank and your DHW cylinder. Link to comment Share on other sites More sharing options...
Tim Pearson Posted January 4, 2023 Author Share Posted January 4, 2023 Ok so updates as follows. 1. Flow Switch Flow switch removed and paddle appears ok. No debris. Connection and wiring checked, appears ok. Option remains to replace with lower switch rate. (ProDave). 2. ASHP pump Grundfoss 20-105 installed aligns to recommended spec. (Att 1). Document confirms runs at max. (per HughF I would assume that LG, like all good heatpump manufacturers, use a PWM controlled primary pump so they have control over the delta-T. So there should be no need to check what speed it is running at.) However, comments (AKJOS) and engineering document (Att 2) suggest inadequate flow with this single 20-105 pump. Option to add additional pump, or upgrade existing (15 to 25?). 3. Two way valve Located two way valve, as per guidance. Re valve response time (Kelvin, ProDave, ReedRichards) there is a manual switch on this valve. I’m unclear on how to check if there is an automatic by-pass. “But most motorised valves take less than 10 seconds to open, and there should be some form of automatic bypass valve to give some flow even when all motorised valves are shut. If you suspect this is your issue, you can manually open most motorised valves, so do that to one of your valves and see if the CH14 error stops.” Question - if it’s two way, then is the default (off/closed position) usually set on DHW or heating? Option remains to - refill the system. - check for ASHP motor running. - manually open two way valve and see if this has any impact. (Any guidance on exactly when to do this? When ASHP is running?). Again, thx all and HNY! Tim Link to comment Share on other sites More sharing options...
dpmiller Posted January 4, 2023 Share Posted January 4, 2023 has the pump got 2 cables plugged in or just 1 mains supply? PWM pumps have a second signal wire to tell them what to do... Link to comment Share on other sites More sharing options...
ReedRichards Posted January 4, 2023 Share Posted January 4, 2023 2 hours ago, Tim Pearson said: 3. Two way valve Located two way valve, as per guidance. Re valve response time (Kelvin, ProDave, ReedRichards) there is a manual switch on this valve. I’m unclear on how to check if there is an automatic by-pass. Locking the arm in the "manual" position should open the valve. I don't know if there is a convention for whether this gives you heating or DHW but if the valve is the problem I think it should give you flow one way or the other. Link to comment Share on other sites More sharing options...
Tim Pearson Posted January 4, 2023 Author Share Posted January 4, 2023 There’s only one cable from the CH pump, to the Honeywell power unit. Att 1. CH and HW both have their own two way valve, means I can manually open individually or together to test. T Link to comment Share on other sites More sharing options...
ReedRichards Posted January 4, 2023 Share Posted January 4, 2023 The picture shows what is probably your central heating pump (too much in shadow to be certain). I have an LG Therma V and AFAIK mine is completely unaware of the presence of the central heating pump. I don't think there is even any option to take control of a central heating pump. In my case I'm not using the Air + Water control option with Load Compensation so there wouldn't be any point anyway. I can also see a pressure gauge which appears to indicate a disparity between the actual water pressure and the indicated pressure. And what looks to be the top of a motorised valve actuator. Link to comment Share on other sites More sharing options...
Tim Pearson Posted January 4, 2023 Author Share Posted January 4, 2023 You are correct. I’ve shown the CH pump, also motorised valve actuator. Pressure is 1.5 bar (ignore red arrow). Reckon my Therma V ASHP is as yours - unaware (not connected/integrated) with the CH pump. Don’t understand this point. “In my case I'm not using the Air + Water control option with Load Compensation so there wouldn't be any point anyway”. thx for FB. T Link to comment Share on other sites More sharing options...
ReedRichards Posted January 4, 2023 Share Posted January 4, 2023 4 hours ago, Tim Pearson said: Don’t understand this point. “In my case I'm not using the Air + Water control option with Load Compensation so there wouldn't be any point anyway”. You can set the Therma V to control based on the just the Leaving Water Temperature or on both the LWT and the room temperature read by the controller, "Air + Water". In the Air + Water mode the controller will try to reach and then maintain whatever room temperature is set. When trying to maintain a set room temperature then modulating the central heating pump could be used to increase or decrease the heat output from the heating so might be a useful control feature. Link to comment Share on other sites More sharing options...
dpmiller Posted January 5, 2023 Share Posted January 5, 2023 ^ not sure if anyone other than RED modulate heating flows in that manner? Has the OP confirmed that this particular ASHP has an internal circulation pump, and that it is actually functioning correctly? Link to comment Share on other sites More sharing options...
Tim Pearson Posted January 13, 2023 Author Share Posted January 13, 2023 Ok so update below. I did locate the two valves for the DHW and CH valves, appeared fine. Having done the previous checks (filter, flow switch, bleed rads) and with the pressure at 1 bar, I decided to refill the system (partially drained). Pressure remained at 1 bar. I then turned all the rads, UFH settings to freeze mode and fired up the AWHP, asking for DHW. The CH 14 error did not reappear and the DHW heated to 45 deg. Then adjusted the UFH settings and the heating came on. That was a week ago - so far no issues. Pressure is still at 1 bar, which I know is on the low end. 3 points. 1. Is it feasible that the 1 bar pressure is “helping” to avoid pump capacity issues? (less pressure, less strain on the pump). 2. After 5 partial drains last year, the forthcoming “service” includes a glycol check. I expect more will need to be added and was told by the UK AWHP distributor that this is an expert job which requires pressure inserted G to dissolve the (very viscous liquid) and avoid blockages cause by G “blobs”. Pressure insertion process is very slow and installers are told to allow 1/2 day on a new install to fill the system with glycol. Not something I could do myself. Does this make sense? 3. My installer service visit has still not been arranged (they still think my system isn’t working). The distributor told me most of the “industry” is focussed on solar installs (higher margins). So much for service and support. Owners of AWHP are going to be stretched to maintain annual service and protect warranty if this continues. Best Tim Link to comment Share on other sites More sharing options...
ReedRichards Posted January 13, 2023 Share Posted January 13, 2023 (edited) I'm pleased that you got your heating working again. My heat pump installer tells me he is now busy with solar. Since there is no plumbing involved in solar PVs and solar water panels are out of fashion I don't really know how he is being occupied but I did not question him further. I don't think the water pressure will affect the pump and once you have got up to 1 bar I doubt that you would need to add much more water to increase the pressure. If you have any leaks this would make them leak faster. Edited January 13, 2023 by ReedRichards Link to comment Share on other sites More sharing options...
PeterW Posted January 14, 2023 Share Posted January 14, 2023 22 hours ago, Tim Pearson said: Is it feasible that the 1 bar pressure is “helping” to avoid pump capacity issues? (less pressure, less strain on the pump). No because the “pump” in a system is actually an open impeller circulator so it doesn’t care as long as there is no air which causes them to cavitate 22 hours ago, Tim Pearson said: was told by the UK AWHP distributor that this is an expert job which requires pressure inserted G to dissolve the (very viscous liquid) and avoid blockages cause by G “blobs” That’s horse $h!t as the glycol you use is normally already diluted and is free flowing. Quickest way to add more (as it’s really antifreeze) is to drain the filter and add at that point 0.5 litres at a time. Easily done yourself. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now