You can check it yourself easily enough Edna, just run your hot tap when the radiators are cold and see if the second pipe from the right gets hot (ignoring the pipe that goes out through the wall). If it does, then your diverter valve is sticking, how long ago did he "replace" it.
ravenheat combi boiler rsf 820-20
- Thread starter edna
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Hi again and thanks for the info, The ex BG eng fitted the DV about, 5 weeks ago. he said the old one was breaking up / crumblng inside ?. Edna.
Dave, it sounds like he's just changed the diaphragm but the backend is still sticking, what do you reckon.
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Never had one do that
Usually just stick.
The more you tell us the more i think you have been had, unfortunately IMHO
Thats what the plumber thinks, and why he needs as much info as possible b4 he tries other things, he wants to eliminate the poss` of it being the DV, (secretly hoping it is.)He has just phoned and wants to know when he does the test suggested, should the DHW switch be on alone, or should the HW/ CH switch be on, or, does it not matter. Hope this makes sense.
Plumber kindly coming around on Wed` to do the test. He did say if its not the DV, do you have any thoughts as to what else it might be. I think after all this I will become a boiler advisor in my spare time, off out soon, working tomorrow, will keep you posted,Thnx for all the advise, one and all. Edna.
Edna, just switch it to h/w only to test it, then like we said, when the rads (and boiler, and pipework) are cool turn a hot tap on and see if the second pipe from the right starts to heat up.
I agree sooey.
Edna, please test the flow pipe from the boiler as we have asked. This is crucial in our fault finding for you
Hi guys, (here we go) I tested the boiler exactly the way you suggested, CH,turned off completely, HW only switched on. The pipe from the boiler taking the water to the taps got very hot, but water coming out of the taps was cold/ luke warm/ nearly hot /then cold again. The big pipe what you called the flow, also got very hot , the radiators didnt get hot as the CH switch was off and the CH thermostat was turned off. I put the CH on the big pipe got hot, so did the radiators, the smaller pipe going to the taps was now cold, and stayed that way. I even bashed the top of the boiler as I have seen posted, a ravenheat eng` suggested, and which worked for someone, but not for me. My plumber friend is going to come round when he is not to busy, meanwhile what do you make of my efforts, appart from the bashing bit, (which I enjoyed the most.) Does this help you to make a diagnosis for me to pass on to the plumber ?. Edna.
When you say that the big CH flow pipe from the boiler got hot when you used the hot tap, where were you touching it? About a foot away from the boiler?
It does indeed sound like the diverter: it does two things... 1) detects the hot tap being opened 2) controls the CH water to heat the hot tap or all the rads
Your diverter seems to be doing (1), but not (2). I saw the same thing when I experimented with a cheapo valve (£25). Replacing it with a genuine Ravenheat one (£100+) made it all work properly.
Do you still have your original valve? It might be that it was faulty on step (1), and the diaphragm can be replaced. That will cost you nothing!
It does indeed sound like the diverter: it does two things... 1) detects the hot tap being opened 2) controls the CH water to heat the hot tap or all the rads
Your diverter seems to be doing (1), but not (2). I saw the same thing when I experimented with a cheapo valve (£25). Replacing it with a genuine Ravenheat one (£100+) made it all work properly.
Do you still have your original valve? It might be that it was faulty on step (1), and the diaphragm can be replaced. That will cost you nothing!
The original DV was replaced with a new one, by an ex BG/,eng`now working for himself, on 24/11/07, (approx 5 weeks ago,) who took the old one away with him, I felt the big pipe CH flow ? on the outside of the boiler going I presume to the radiators , although they did not get hot as the CH was isolated. This is what was suggested that I do, to test if the DV was working properly ?. This is as much as I am able to tell you. The thing that seems funny to me is why if the small hot water pipe ( also on the outside of the boiler ( going to the tap is hot ), why isnt the water coming out also hot ?. Can you explain in laymans language please, having concidered all the explanation previously posted. thnxs, Edna.
Hi Dave, I didnt go under the boiler to isolate the CH, (are you kidding) I just set the switch on the boiler to hot water only, and turned the thermometer in the hallway to zero. Then turned on the hot water tap to see which pipes got hot, was this not correct ?. Edna
The CH flow pipe getting hot (when the CH is off and the HW tap is open) is incorrect, and does indicate a faulty DV. If you run the HW tap for a long time (10 mins), the rads will probably start to warm.
It does seem strange, though, that you've had the same issue with your old DV. So unless the ex-BG guy has also supplied a dud, then perhaps the fault is elsewhere?
When you run the HW tap, does the boiler stay lit? (no cutting out)
The small HW pipe being hot is interesting! How hot? Assuming your HW and CH temperature dials are on max, the HW should be about 65 degrees C, and the CH about 85 degrees C.
Yes the flames stay on until the tap turned off. The small pipe is roughly the same temp as the big pipe,( although I havn`t tried this with the hw & ch on together, ) both of these pipes are about a foot or so from the boiler, they come from underneath, and appear on the left hand side of the boiler as you look at it. The plumber was asking if the hot water stat was faulty as there is no audible click when you turn the knob either way. also he took out the sensor connected to this stat and nothing happened. Have you managed to read all the info given from the beginning of this saga?. When he comes hese going to read what has been said in reply, and take it from there. Meanwhile the problem continous, but thanks for all your help, I have written everything down thats happened , and will answer any questions, (if I can) if you have any more suggestions let me know, I will post any news as and when, Edna.
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