The Dogmother Posted January 25, 2014 Share Posted January 25, 2014 Anyone on here know owt about central heating? I have a combi boiler, about 8-10 years old, never had any problems with it until now. I don't usually use the bath, but had one the other night and noticed that the hot water was running tepid. I spoke to my heating engineer the next day, and he suggested turning the water flow in the hot bath tap down and that it would then run hot... sure enough it does, but it takes about 15 minutes to run a bath! All the other hot taps seem to be fine. I can live with this as I almost never use it, preferring to shower, but I am interested to know what causes the problem and whether I ought to get it fixed if it stands a chance of becoming a bigger problem. Quote Link to comment Share on other sites More sharing options...
Lavenders_Blue Posted January 25, 2014 Share Posted January 25, 2014 At a wild guess, has it lost pressure? Mine did this recently and it was very simple to fix - twisting a couple of k"Ooops, word censored!"s in the airing cupboard to repressurize the system (and then letting the air out of a radiator as I overpressurized it ). Might be worth checking. Edit - forget that, I've just noticed that all the other taps are fine. Quote Link to comment Share on other sites More sharing options...
The Dogmother Posted January 25, 2014 Author Share Posted January 25, 2014 Thanks L_B, that was the first thing I checked Quote Link to comment Share on other sites More sharing options...
sjp Posted January 26, 2014 Share Posted January 26, 2014 are the pipes to the bath 22mm by any chance. as I have the same problem with my hot water boiler it's less than 5 years old and has a factory set temperature that can't be increased and a high temperature cut off that's over sensitive at this time of year when the water from the mains is really cold the boiler can't heat the water quick enough for the bath due to the amount of water that the 22mm pipes pull through and I can't lower the flow through the taps enough to get the water hot enough without the thermal cut out tripping . service engineer can't/won't see past the fact that the factory setting are to low for my needs. I should add the pipes were there before I had to have a new boiler and the sinks or ok as they are on 15mm pipe Quote Link to comment Share on other sites More sharing options...
The Dogmother Posted January 26, 2014 Author Share Posted January 26, 2014 That sounds as if it might be the problem sjp - thanks. If that's the case, then the problem ought to sort itself in the warmer weather I guess... albeit temporarily. Next time my heating engineer/plumber is out for something else, i will ask if he can alter the factory settings as it's a right pain. I hardly use the bath, and it's OK when used through the shower part of the bath mixer, but The boy likes a bath when he visits. Quote Link to comment Share on other sites More sharing options...
Eggasperated Posted January 26, 2014 Share Posted January 26, 2014 That's interesting, I had a new boiler installed and as we have a digital display for the hot water temperature I could see that the water was not getting above 55 degrees in the tank even with the boiler at its highest temperature, the rads were also barely getting the rooms warm enough as the outside temperature got lower. As the daughter of a former central heating engineer (sadly no longer with us) I was not prepared to settle for this even tho' I was told the factory setting did not allow the boiler to run any hotter; eventually I was told I could override the setting by removing a pin inside the boiler thermostat. It then only needed the smallest tweak to get the water and rads to a good temperature. The technical dept at the boiler manufacturer were able to give me this information - after a bit of badgering, and the boiler has been fine ever since. Edit: I can see you are discussing combi boilers but I think the principle is the same as with condensing boilers when it comes to factory settings. Quote Link to comment Share on other sites More sharing options...
The Dogmother Posted January 26, 2014 Author Share Posted January 26, 2014 Thanks Eggasperated, but I think the problem is with the pipe width to the bath, and the colder ambient temperature at the moment, rather than a factory setting. Quote Link to comment Share on other sites More sharing options...
The Dogmother Posted February 13, 2014 Author Share Posted February 13, 2014 Jut an update on this - the hot water problem started to affect the shower, so I called out the heating engineer. He has ordered another heat exchanger, but won't replace the existing one if he can clean it up and sort the problem. Hopefully I'll get home today and have decent hot water out of all of the taps! Quote Link to comment Share on other sites More sharing options...
Patricia W Posted February 13, 2014 Share Posted February 13, 2014 Fingers crossed for you! Quote Link to comment Share on other sites More sharing options...
The Dogmother Posted February 13, 2014 Author Share Posted February 13, 2014 Thanks, at least we can use the bath, but it take so long to run as we have to keep the water flow pressure down in order to keep the temperature up. I am missing a hot shower. Quote Link to comment Share on other sites More sharing options...
The Dogmother Posted February 15, 2014 Author Share Posted February 15, 2014 Fast losing my patience with this now Friday, it was all fixed... new heat exchanger in the boiler, shower valve calibrated for temperature = lovely hot shower on Friday night. Just had a shower, and it was body temperature at best, as was the water coming out of the bath taps. If I had the money, I'd say 's"Ooops, word censored!" the boiler and get a new one!' Quote Link to comment Share on other sites More sharing options...
Space Chick Posted February 15, 2014 Share Posted February 15, 2014 Sounds insane but it could be a wind issue. Occasionally my shower goes cold and then goes hot again. I've had 2 boiler engineers out who have said my boiler even though it's 11 years old, is working perfectly. Then a bassist friend told me of an issue that happens when wind blows at the venting bit, and the hot, cold issue happens. I thought he was nuts until I realised that it only happens when it's windy. It really is bizarre! Quote Link to comment Share on other sites More sharing options...
Lavenders_Blue Posted February 15, 2014 Share Posted February 15, 2014 Space Chick, that's really interesting. My shower has been going suddenly hot/cold over the last week or so, almost as if someone has been running a tap in another room (but when I have been home alone - spooky!). Wind affecting the vent would explain this perfectly given the weather we're having at the moment! Quote Link to comment Share on other sites More sharing options...
The Dogmother Posted February 15, 2014 Author Share Posted February 15, 2014 Good theory, but I'm afraid that it started before the windy weather, and it's not windy at the moment, so probably not the cause. Quote Link to comment Share on other sites More sharing options...
