no hot water plumbing help needed please!!!!

[kittycat68]

hi after advice from a plumber. Have strange problem a few weeks ago the hot taps in the hose started to run only cold water, then sometimes hot then sometimes cold etc!!! Called in boiler man, have oil combi boiler, boiler man came five times almost stripping the boiler also talked to manufatoror couldnt find any problem with boiler at all said it must be a plumbing problem, didnt charge me as he said he felt bad as couldnt find the problem! xmas now over and would like to fix the problem but dont have much money to call in plumber as on benefits am very diy handy so if anyone can tell me the problem i could try to fix it myself

if anyone knows a plumber could they ask them for me too please thanks

Not plumber but DH darn handy with plumbing and he's a builder so gets to see a bit off stuff. His first thought was 'are you in a hard water area? just that the flow switch tends to fur up and it's common on combi boilers. Just a thought!

hi yes we are in a hard water area i forgot to mention before we dont have any drop in pressure either and as its on all taps couldnt see how its plumbing problem.do you think i need to get the boiler company abck then?

bumping!!

bumping again anyone any more thoughts

We had exactly this problem just before Xmas. Have you got a megaflo or a hot water storage tank and/or a mixer tap/shower valve higher than the hot water supply? In our case a faulty shower mixer valve in the loft was diverting cold water down the hot water pipe to the megaflow and preventing the hot water coming out, hence intermittent/no hot water. The boiler and megaflo were both working fine, as we discovered at vast expense. I eventually fixed it by fiddling with the shower thermostat until hot water was restored to all the taps, and have now disabled the offending shower by removing the thermostat handle until I can get the valve replaced. Might be worth a try?

all my taps are my taps in the house and i also have a shower mixer too ill try replacing the shower mixer first as this wont damage any tiles etc and see what hapens thanks!!

you said you have a combi boiler. Therefore I deduce no hot water cylinder or cold water tank. Therefore it will not be a mixer letting by since the hot and cold water will be at the same pressure.

I would have thought the flow switch is not detecting that hot water is running. Turn on the hot bath tap, run it into a bucket while timing it, and see how many litres per minute you get. Then turn on all the hot taps in the house at the same time and see what happens to the HW temp. However it shouldn't be that because a competent heating engineer would spot it.

I'm a bit surprised you have an oil-fired combi, they must be quite rare.