Post by CWatters on Sep 22nd, 2011, 10:08pm
Valves are electrically operated (so they have a wire) and look something like this. How many do you have and which type...
Two port:
Three port:
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DIY Forum >> Plumbing Questions >> Water too hot https://www.askthetrades.co.uk/cgi-bin/yabb/YaBB.pl?num=1316681300 Message started by Pineapple on Sep 22nd, 2011, 9:48am |
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Title: Water too hot Post by Pineapple on Sep 22nd, 2011, 9:48am Hi Our hot water is hotter than normal - too hot to keep your hands in but not scalding. I turned down the cylinder stat from 60c but it hasn't made any difference. Turning it right down makes the boiler go off and right up makes it go on, so I'm wondering what else could be at fault? Thank you. |
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Title: Re: Water too hot Post by thescruff on Sep 22nd, 2011, 11:36am Hi. Could be a couple of things but we need to know more about the system. Could be a faulty cylinder stat, or a motorized valve. Is the problem worse when the heating is on. |
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Title: Re: Water too hot Post by Pineapple on Sep 22nd, 2011, 11:57am Haven't tried it with the heating on due to the time of year. The system is gravity fed. The heating can come on independently of the hot water. The bathroom radiator comes on with the hot water. The boiler is a Potterton Prima F. We used to have to replace the motorised valves every other year as they were so unreliable, but we haven't had any bother recently. |
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Title: Re: Water too hot Post by thescruff on Sep 22nd, 2011, 2:09pm I would imagine it's fully pumped, do you have 1 x 3 port valve or 2 x 2 port valves. |
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Title: Re: Water too hot Post by Pineapple on Sep 22nd, 2011, 9:54pm thescruff wrote on Sep 22nd, 2011, 2:09pm:
I wouldn't know the difference. |
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Title: Re: Water too hot Post by CWatters on Sep 22nd, 2011, 10:08pm Valves are electrically operated (so they have a wire) and look something like this. How many do you have and which type... Two port: Three port: |
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Title: Re: Water too hot Post by Pineapple on Sep 23rd, 2011, 7:20am Thanks for the pictures. My system is a two port. (BTW, if it comes to it, is it possible to change the box on top without having to drain down the system?) |
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Title: Re: Water too hot Post by thescruff on Sep 23rd, 2011, 10:32am Do you have one or two of them. Need info, make and models etc. |
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Title: Re: Water too hot Post by Pineapple on Sep 23rd, 2011, 11:31am The two valves are made by Honeywell. The writing on the top is F3-9419. http://www.mediafire.com/?b3zdnvsgcvydqdd http://www.mediafire.com/?wl21kac8b6w7hd1 |
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Title: Re: Water too hot Post by thescruff on Sep 23rd, 2011, 1:30pm Don't appreciate getting spammed by mediafire or anyone else. Use the forum facility next time please. [smiley=headbang.gif] |
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Title: Re: Water too hot Post by Pineapple on Sep 23rd, 2011, 10:43pm thescruff wrote on Sep 23rd, 2011, 1:30pm:
Apologies...I couldn't see how to attach pics. I dislike spam as much as the next guy. |
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Title: Re: Water too hot Post by thescruff on Sep 23rd, 2011, 11:32pm I would change the cylinder stat, or make sure it's making a good contact to the cylinder |
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Title: Re: Water too hot Post by Pineapple on Sep 23rd, 2011, 11:45pm Cheers, I'll change the stat. |
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Title: Re: Water too hot Post by thescruff on Sep 24th, 2011, 9:10am Check whether the cylinder stat is closing the MV and shutting the boiler off, in the HWS onltmode |
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Title: Re: Water too hot Post by CWatters on Sep 24th, 2011, 9:51am wrote on Sep 22nd, 2011, 9:48am:
If it really is controlling the boiler (and the central heating is off) it's hard to see what could account for the water getting too hot. However, normally you only have to turn the dial a few degrees for it to click and the boiler fire up or shut down. If it only controls the boiler when you turn it all the way up/down then I agree worth trying another stat. One problem with hot water systems is that 60C is hot enough to burn a child but if you turn it down there is a risk of Legionaires disease. I did wonder if somone had just turned the stat up. eg perhaps it set to say 50C before and someone turned it up or knocked it? Sorry if thats a rather obvious suggestion. |
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Title: Re: Water too hot Post by thescruff on Sep 24th, 2011, 11:15am The stat should be 50-55c depending where it positioned |
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Title: Re: Water too hot Post by Pineapple on Sep 24th, 2011, 11:17am thescruff wrote on Sep 24th, 2011, 9:10am:
I moved the stat down to 55c from 60c, which I understand is the recommended setting. Sorry to be dim, but are you saying that the spring-loaded lever should move, or do I have to listen out for a click? Also, what is HWS on/tmode? |
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Title: Re: Water too hot Post by Pineapple on Sep 24th, 2011, 11:23am CWatters wrote on Sep 24th, 2011, 9:51am:
I'm beginning to think it's all in my mind ::) |
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Title: Re: Water too hot Post by thescruff on Sep 24th, 2011, 12:05pm When the hot water (HWS) is off, there should be resistance on the manual slider on the end of the MV, when the HWS is calling there should be no resistance. Go through the program. Turn the HWS on on the programmer. The boiler and pump should run provided the cylinder stat is calling. Turn the stat down and the boiler should stop, the pump may run on for a few minutes or so. Now turn the HWS off and the HTG on, check whether the pipe going to the cylinder still gets hot. |
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Title: Re: Water too hot Post by Pineapple on Sep 24th, 2011, 12:50pm Many thanks...will do. Update...the supply pipe stayed cool when the c/h was turned on. |
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Title: Re: Water too hot Post by Pineapple on Sep 25th, 2011, 10:34am I guess that the valve is working as it should. |
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Title: Re: Water too hot Post by thescruff on Sep 25th, 2011, 10:54am You supposed to post the results of the tests. |
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Title: Re: Water too hot Post by Pineapple on Sep 25th, 2011, 10:58am thescruff wrote on Sep 25th, 2011, 10:54am:
From earlier post: Update...the supply pipe stayed cool when the c/h was turned on. |
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Title: Re: Water too hot Post by thescruff on Sep 25th, 2011, 11:56am That's good news. What have you got the boiler stat set at, try turning it down. |
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Title: Re: Water too hot Post by Pineapple on Sep 25th, 2011, 1:54pm The boiler stat is at 4. For info, that governs just the c/h, yes? |
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Title: Re: Water too hot Post by thescruff on Sep 25th, 2011, 1:56pm wrote on Sep 25th, 2011, 1:54pm:
No the boiler stat is both. The room stat controls the htg |
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Title: Re: Water too hot Post by Pineapple on Sep 25th, 2011, 2:20pm Showing my ignorance again, why would you have the boiler stat and the cylinder stat both controlling the water temp in the h/w cylinder? |
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Title: Re: Water too hot Post by greg on Sep 25th, 2011, 4:37pm The cylinder stat controls the temperature of the water stored in the cylinder, the boiler stat controls the temperature of the water passing through the boiler. If you had your cylinder stat set to 60deg and your boiler stat set to 50deg, then your cylinder stat would never be satisfied as the max temp the water in the cylinder would reach would be 50deg. |
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Title: Re: Water too hot Post by CWatters on Sep 25th, 2011, 7:15pm I think it's time to actually measure the temperature of water coming out of the taps with a thermometer :-) Another crazy thought.... Has someone left the immersion heater on by mistake? |
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Title: Re: Water too hot Post by Pineapple on Sep 25th, 2011, 8:46pm CWatters wrote on Sep 25th, 2011, 7:15pm:
I can't find a thermometer that measures above 50c. The immersion heater has a socket with a light that comes on when drawing power. I've now turned the boiler stat down to three, which is probably more of a summer setting. |
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