OK I’m confounded by an issue with our hot water system which is an electrical storage heater and until 2 days ago it was running fine.
However we now only get hot water in certain circumstances (below), so if there is anyone out there that could throw some light on it, it would be much appreciated?
Water in storage tank is hot, the tank is 4 years old
Water out of TPR is hot, I have tested by lifting the valve handle and flushing it, hot water comes out the top. TPR is about 1 year old.
There is no apparent water coming out from the TPR drain that exits through the wall.
Water out of all hot taps is cold unless…
Hot tap in laundry is cold but if I open it right up and then it’s hot. If I start to close the tap down it goes back to being cold. Laundry tap is furthest from storage tank.
Kitchen Hot tap is cold unless I open up laundry tap full and the kitchen tap runs hot until I turn laundry tap off when the kitchen taps goes to luke warm and then cold. Tap is mid-way between storage tank and laundry
Hot tap in bathroom has the same issues as kitchen tap. This tap is almost directly above the storage tank.
Shower in bathroom is the same as bathroom tap unless I remove the shower head, which is a water saving device after which it runs hot. As soon as I replace the shower head it runs cold after a minute.
There is no tempering valve in the system to add in cold water.
I’m assuming this must be a pressure related issue, but can’t understand why it is an issue suddenly.
Hot water system issues - help
Comments
Are you sure you haven't got a tempering valve as I think they became mandatory to be fitted to all new/ replaced systems in 2012. Plus it sounds like a tempering valve problem either within the mechanics of thevalve or the filter at the hot water inlet of the valve. Also some HWS have a inlet regulator on the cold water side. AFAIK the TPR valve is only connected to the tank and would be unlikely to affect the hot water to the house, assuming it is not leaking.
As mskeggs says it's a job for a plumber.
Tempering valve/thermomixing valve fault.
Elppa8 is right, they are mandatory unless you are in a old house that has not been re-plumbed. They have an adjustment knob (try to rotate both ways and check temperature) but probably you will need to replace it. Easy if you are handy with the tools. Do not forget to close the water from the mains before you do. Or pay $150-200 for a plumber to do it.
thanks for the replies all
Mskeggs, I believe that the TPR only affects the internal pressure/temp and has not effect on the outlets as it is not in that part of the outlet component of system but rather in the tank itself.
Elppa8, yes I've followed the outlet all the way through and no tempering valve is in place. Your suggestion re the inlet regulator maybe the answer, there is one fitted on the inlet side so that may be the cause. Thanks a lot
Re calling plumbers, I wanted to try and get an idea what it may be before calling, the last plumber I called stitched me up, once bitten twice shy they say, I now have zero trust!
regards
Johnthanks Maxi, house is 75+ years old and was last replumbed in the 60's apparently. Definitely no tempering valve, been under the house and along all pipework and also along all internal pipework including in cupboards/under sinks etc.
Thanks for your assitance
I you don't have a thermomixing valve or similar somewhere. How can you get cold water at all when using the hot water tap? In a simple system like my 65yo house, only hot water is connected to hotwater pipes post the hws. If that's blocked off nothing flows through a hot tap.
Agreed, if there was a tempering valve fitted when the HWS was replaced it would probably fitted nearly direct to the tank as that would have been easier plumbing.
Could the tank itself have a tempering valve internally? Easy enough to check if cold water flows out the tanks hot water outlet while you run a hotwater tap in the house (ie by temp change or vibration or as you said by lifting the valve handle). If so the tank instructions should say.
Anyway, there can't be cold water coming out of hot taps without a bypass.
Probably not a lot of help in this situation, but I had a HWS that seemed to be getting low on pressure, eventually slowing all taps down to a dribble. I went to a plumbing supplies and asked them if it would be the pressure control valve on the HWS outlet by showing them a photo of the setup. They said no chance, that never happens. I took it off and the outlet flow, to a bucket, was perfect, put it back on and back to a trickle, the valve was blocked. New valve, from Bunnings as the plumbing supplies joint was now shut, and all returned to good.
It might be worth asking at a plumbing supplies place, some of them are pretty good. Take along some photos of the setup.
I suppose it's also possible that a mixer tap somewhere failed, allowing hot & cold to mix. While renovating we had some dumbarses decide to temporarily replace one with a simple cap, which gave us cold water out every other hot tap in the house…
Have you recently pissed off any plumbers and then heard strange noises early on the morning before the problems started ???
May be a cross connection between a mixer tap or appliance. If the hot water unit has a pressure limiting valve on it, the cold water pressure will overrun the hot and may cause luke warm water. This can be easily tested by isolating the hot water system and turning on a hot tap. If water still comes out of the hot tap - you have a cross connection. If you interested Hot Water Fault finding or informationtake a look at this page for some useful tips.
Some build up of scale or something is clogging the TPR valve (probably), so it is only functioning proerly at full pressure when the tap is wide?
Call a plumber, its what they do.