PLEASE HELP!! We have a 1970's 4 bed house with a straight-through combi boiler in the garage that we've had for about 13 years when the tank was removed.
We've never had a consistent supply of hot water and anything other than 1 shower running reduces the water pressure to a point where the boiler cuts out & go back to cold.
It turns out that the mains water pressure is OK from Anglian water's perspective but is at the min requirement for the Brit gas boiler.
So we currently leave the hot tap / shower running for several minutes to get any hot water into the upstairs bathrooms (for a sink-full or shower) & we're fed up!!
Would like to change our hot water system and include some green solar aspects to heat and manage waste water. We are wasting 80% of the water we use when trying to get a sinkful & many litres when trying to get a shower. If the boiler cuts out then we have to start the process again.
There are so many possible angles here, this reply could end up as an essay!
If you cannot improve the flow rate of the mains supply you could move back to a stored supply of water, but this is very much a retrograde step. Traditional stored water is not considered "wholesome" for obvious reasons.
If you are considering the green aspect of using "grey" water, then this is a totally different avenue, but it is now pretty much universal to see header tanks done away with in favour of fully sealed systems.
Solar heating can be applied to both open and sealed systems and you might with a bit of ingenuity, use your existing combi boiler to supply the primary hot water supply.
I wouldn't consider going this route immediately though. Have you really exhausted tackling Anglian Water??? Supply companies will duck and dive to avoid responsibility unless you really pressurise them (sorry) to do something. It is not unusual to find they perform tests when the demand is low and consequently the pressure high for example.
What type of pipe is your supply, how old is it, how far is it from the mains? What about neighbours? Has anyone else complained? If several people in a street complain, it can occasionally result in a sudden increase in pressure that the water board apparently seems unable to explain!
You might even find simply upgrading the supply to your house from the street to 25 or 32mm mdpe will solve your problem.
Hi Plumbbob- thanks for the response. Will ask the neighbours about their water(!!) & maybe get back to Anglian water to retest to incoming pressure.
Obviously also feel a bit misled that the combi was happily installed (i.e. sold to me) by Brit Gas at the time without any reference to the supply pressure. Reviewing the spec of the boiler clearly reveals it needs a higher input pressure than we're getting.
This isn't an area I'm familiar with but is there a way of using our existing system to feed the water through solar panels to an insulated storage tank in the loft (bit like a big flask) that could supply both showers and hot taps? Would the head of pressure be sufficient?
MikeB9 wrote:Obviously also feel a bit misled that the combi was happily installed (i.e. sold to me) by Brit Gas at the time without any reference to the supply pressure. Reviewing the spec of the boiler clearly reveals it needs a higher input pressure than we're getting.
Testing and recording the flow rate of the hot water is part of the boiler commissioning so either the rate has fallen since the install or the result was fudged in the first place. Do you have the any records filled out by the installer?
MikeB9 wrote: This isn't an area I'm familiar with but is there a way of using our existing system to feed the water through solar panels to an insulated storage tank in the loft (bit like a big flask) that could supply both showers and hot taps? Would the head of pressure be sufficient?
Yes. Solar heating works by heating water in a large store cylinder. The combi might be able to be coupled in a "S" style plan to top up the stored hot water should the solar be unable to cope with demand.
Although it's going to cost a bob or two, this is all run-of-the-mill stuff. The serious consideration must be whether to use header tanks in the loft or get the mains pressure sorted so the system can be sealed.
MikeB9 wrote: ........to an insulated storage tank in the loft (bit like a big flask) that could supply both showers and hot taps? Would the head of pressure be sufficient?
In theory, the bottom of a header tank has to be at least one metre above the top of a hot water cylinder which is often difficult in a traditional loft. There might be ways round this, but I can't say for certain as obviously, this would only be guesswork. You would almost certainly get the taps working and probably the shower too, but really you need to get a quote from an experienced heating engineer.
The only way you can increase the flow rate would be to renew the mains supply to the house with a larger diameter pipe - if the pipe is old you may find the pipe is partially crushed especially if under a drive.
However you need to ensure the neighbours are right about their flow rate, as you my replace the pipe to fin the flow rate is the norm.
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