Ask a plumber/heating ‘engineer’ anything
Discussion
dhutch said:
Vaillant EcoFit Pure 825 making a funny noise in heating mode?
https://youtube.com/shorts/WhmcYc2rMDE?si=uLoxTK11...
Thoughts welcome....
Anyone got any suggestions for the MIL boiler?https://youtube.com/shorts/WhmcYc2rMDE?si=uLoxTK11...
Thoughts welcome....
How would I isolate the hot tap so I can look at why there's water around it? There's no cut-off valve on the pipe, will the freeze spray work and give me long enough to figure out how to dismantle the tap and put it back together? I could do it once the water in the pipe has run cold. If it won't work, or for more time to see what's going on, what is the next way to stop it spraying water when I remove it? I have a hot water cylinder upstairs which serves the taps and the central heating ( I think ), tap in question is downstairs, would the cylinder normally have a cut-off on the outlet perhaps?
Yes, usually the HW cylinder has cold water inlet isolation, plus hot water outlet and balanced cold water isolation valves.
To cover any eventuality, turn all three off, turn the basin hot tap on, and if there's another hot tap at a lower level, turn that on too. This will drain the small amount of water in the hot pipework, allowing you to service the tap.
Once all done, close the taps, reinstate the water supplies, and go round the gaff, turning on all the hot water taps, they may splutter before returning to full flow as the air is displaced in the system.
To cover any eventuality, turn all three off, turn the basin hot tap on, and if there's another hot tap at a lower level, turn that on too. This will drain the small amount of water in the hot pipework, allowing you to service the tap.
Once all done, close the taps, reinstate the water supplies, and go round the gaff, turning on all the hot water taps, they may splutter before returning to full flow as the air is displaced in the system.
DoubleSix said:
How do i remove this?
Grohe GD2
Comprehensive maintenance instructions here > https://www.schneordesign.com/diy/diy-misc/grohe-g...Grohe GD2
Regbuser said:
Yes, usually the HW cylinder has cold water inlet isolation, plus hot water outlet and balanced cold water isolation valves.
To cover any eventuality, turn all three off, turn the basin hot tap on, and if there's another hot tap at a lower level, turn that on too. This will drain the small amount of water in the hot pipework, allowing you to service the tap.
Once all done, close the taps, reinstate the water supplies, and go round the gaff, turning on all the hot water taps, they may splutter before returning to full flow as the air is displaced in the system.
Thanks, I'm still nervous about messing with water but at least I won't be on the clock while something melts.To cover any eventuality, turn all three off, turn the basin hot tap on, and if there's another hot tap at a lower level, turn that on too. This will drain the small amount of water in the hot pipework, allowing you to service the tap.
Once all done, close the taps, reinstate the water supplies, and go round the gaff, turning on all the hot water taps, they may splutter before returning to full flow as the air is displaced in the system.
I have a question….
We have two mains water supplies supplying two combi boilers. One of the combis is now dead but I’ve linked the working combi into both systems (and turned the stop tap off at one water supply) and it all functions fine. It’s just not great with two showers running.
A plumber has suggested that in order to keep a decent flow of hot water from the remaining combi I could run one mains supply as the cold feed to the whole house and the other mains supply to the combi boiler to provide the hot water to the house. This way I’d have maximum flow for the hot water at all times and flushing a cold-fed toilet wouldn’t affect the shower if you were running it at the same time.
Seems easy enough to do to me but are there any risks doing this with excess pressure on the system or balance issues at the outlets?
We have two mains water supplies supplying two combi boilers. One of the combis is now dead but I’ve linked the working combi into both systems (and turned the stop tap off at one water supply) and it all functions fine. It’s just not great with two showers running.
A plumber has suggested that in order to keep a decent flow of hot water from the remaining combi I could run one mains supply as the cold feed to the whole house and the other mains supply to the combi boiler to provide the hot water to the house. This way I’d have maximum flow for the hot water at all times and flushing a cold-fed toilet wouldn’t affect the shower if you were running it at the same time.
Seems easy enough to do to me but are there any risks doing this with excess pressure on the system or balance issues at the outlets?
Trustmeimadoctor said:
It doesn't matter how many lpm you supply to the combi it can only output so much at a specific rise
Of course. But if the current supply from a single mains is 15 litres per minute and the boiler can heat 15 litres per minute, flushing a toilet will obviously reduce the hot water produced by a significant amount. But if the cold has its own supply it wouldn’t be affected and the boiler would still put out 15 lpm from the other supply. I’m also not sure how much the digital shower mixers add cold water to the hot to get it to the set temperature. The DHW on the boiler is set to 55 degrees but the digital showers are set to 40 degrees; therefore they must be adding cold water to the hot water.
Given that the digital showers have a max output of 15lpm my logic (and I assume the plumber’s) is that if they have a separate cold supply any drop in flow from running two at once should be minimal because they’re not sharing a total mains flow of 15lpm but sharing 15lpm of hot and another 15lpm of cold.
It’s a couple of metres of simple pipe work to modify so I’m tempted to try it to see if it makes a difference. It would save me many thousands of pounds in lieu of the alternative which is adding an unvented cylinder to one of the mains supplies. I just want to make sure I’m not going to have too much pressure in the system somewhere.
It's a good idea for you but was wanting to check you didn't think you were going to end up with something you weren't
Honestly I'd reduce the output of the showers with flow restrictors you dont need 15lpm from a shower I'd try 9lpm see how you get on and see if you can on with even less they cost pennies on eBay etc
Honestly I'd reduce the output of the showers with flow restrictors you dont need 15lpm from a shower I'd try 9lpm see how you get on and see if you can on with even less they cost pennies on eBay etc
I think the first think I would be doing it checking the flowrate at the isolation valves for the two supplies you have, which should give you a good indication of the flow rates available at each. Because you might find a) one is significantly better than the other b) one or other of them provides significantly more or les than the 15l/min being banded about.
You could also very easily measure the static pressure of both supplies, although given they presumably both come of the same water main, fairly close together, I expect this will be fairly constant.
Depending on what you find you can then make a better assessment of if the proposal makes sense.
Equally, if its currently lead of 15mm copper, you might get as good or better an effect from having the pipe between the stopcock in the road and the incoming supply replaced.
If I am right, this is two semi-detached properties which have now been combined to make a single home, hence the duplicity.
You could also very easily measure the static pressure of both supplies, although given they presumably both come of the same water main, fairly close together, I expect this will be fairly constant.
Depending on what you find you can then make a better assessment of if the proposal makes sense.
Equally, if its currently lead of 15mm copper, you might get as good or better an effect from having the pipe between the stopcock in the road and the incoming supply replaced.
If I am right, this is two semi-detached properties which have now been combined to make a single home, hence the duplicity.
My hot water pressure is crap, I'm guessing its all down to the old hot water tank not being pressured.
Is it as simple as changing the tank to a pressurised system & changing the power showers and it would work ok?
Whats the ballpark figure on this?
I kinda want to keep the tank as will be getting solar soon and will be able to use immersion to heat the water in the summer.
Or just get a combi?
Is it as simple as changing the tank to a pressurised system & changing the power showers and it would work ok?
Whats the ballpark figure on this?
I kinda want to keep the tank as will be getting solar soon and will be able to use immersion to heat the water in the summer.
Or just get a combi?
pacenotes said:
My hot water pressure is crap, I'm guessing its all down to the old hot water tank not being pressured.
Is it as simple as changing the tank to a pressurised system & changing the power showers and it would work ok?
Whats the ballpark figure on this?
It depends. There are lots of past threads on this,, as well as the 'combi or no' argument.Is it as simple as changing the tank to a pressurised system & changing the power showers and it would work ok?
Whats the ballpark figure on this?
If you have a good incoming flow rate (good pipe size and or good pressure) then changing a vented hot water tank to an unvented, mains pressure, hot water tank can give a good performance boost and is what we did four years ago in our house. It works well.
However if you have poor incoming flow, you lose the buffer you currently have of a large tank of cold water in the attic, and or the shower pump you currently have to boost the pressure/flow. Unless you also fit a mains pressure accumulator and or pump system.
A decent size unvented tank is around a grand, plus a day or two of a plumber time to fit, less whatever you or then can weigh the old copper tank in for.
As you say showers with an 's' I presume you have more than one? How many bedrooms/people are at the house?
If thinking of thermal solar, ensure the new tank is suitable, if thinking solar pv then ensure the tank has an immersion heater, although most do.
We went with an OSO Supercoil, because they looked nice and we couldn't get a OSO Deltacoil readily, I want the expansion accumulator to be internal for maintenance and longevity reasons. Joule offer a budget range, Worcester Bosch and Viessmann both do their own tanks, Megaflow and others do a tanks with internal expansion bubble and floating diaphragm.
dhutch said:
I think the first think I would be doing it checking the flowrate at the isolation valves for the two supplies you have, which should give you a good indication of the flow rates available at each. Because you might find a) one is significantly better than the other b) one or other of them provides significantly more or les than the 15l/min being banded about.
You could also very easily measure the static pressure of both supplies, although given they presumably both come of the same water main, fairly close together, I expect this will be fairly constant.
Depending on what you find you can then make a better assessment of if the proposal makes sense.
Equally, if its currently lead of 15mm copper, you might get as good or better an effect from having the pipe between the stopcock in the road and the incoming supply replaced.
If I am right, this is two semi-detached properties which have now been combined to make a single home, hence the duplicity.
The house was a large detached but was split in two and is now converted back to a single large detached - hence the dual utilities, which does have upsides. You could also very easily measure the static pressure of both supplies, although given they presumably both come of the same water main, fairly close together, I expect this will be fairly constant.
Depending on what you find you can then make a better assessment of if the proposal makes sense.
Equally, if its currently lead of 15mm copper, you might get as good or better an effect from having the pipe between the stopcock in the road and the incoming supply replaced.
If I am right, this is two semi-detached properties which have now been combined to make a single home, hence the duplicity.
I’ve just replaced the mains run from one stop tap with 22mm pipe while the other remains as 15mm. I’ve not actually seen how good the flow is from the 22mm yet but it was pretty good just off the 15. Personally I think the hot supply will benefit most from having the 22mm feed.
Just to give a perspective behind this, the reason for this work was to simplify the system and avoid having two boilers - one of which is now dead and the other being in its twilight years.
I was considering keeping one boiler and fitting an unvented cylinder to it but also considering a massive 45kw boiler with a huge hot water flow rate.
The quotes I’ve had are £5200 for the massive combi, with the boiler itself being about £2800 and £2.4k of labour!
And the quote for adding an unvented cylinder to the remaining combi boiler was £3200 but with the risk that that combi might expire in the next few years incurring additional cost.
Or I fiddle with the pipework for like I’m proposing and see if the single existing combi can give us an acceptable flow from two showers without the drawback of flushing a toilet or brushing teeth causing a drop in the hot water flow. I’ve probably got all the pipe and fitting I need in the shed!
why do you need a 45KW boiler? what has that been based on ?
a storage combi could be good for you provides high flow rates as it has a buffer tank inside the viesmann 222 actually has a 100L tank apparently that has the same ability as a normal 350L tank
a storage combi could be good for you provides high flow rates as it has a buffer tank inside the viesmann 222 actually has a 100L tank apparently that has the same ability as a normal 350L tank
Edited by Trustmeimadoctor on Friday 12th April 15:46
Trustmeimadoctor said:
why do you need a 45KW boiler? what has that been based on ?
a storage combi could be good for you provides high flow rates as it has a buffer tank inside the viesmann 222 actually has a 100L tank apparently that has the same ability as a normal 350L tank
It’s based on being able to run two showers and a bathroom, so the hot water flow side of things. He said he could then down rate - or whatever the term is - the CH side of it, although I think it’s ‘only’ 35kw for that anyway. It’s not my preference, just an option. a storage combi could be good for you provides high flow rates as it has a buffer tank inside the viesmann 222 actually has a 100L tank apparently that has the same ability as a normal 350L tank
Edited by Trustmeimadoctor on Friday 12th April 15:46
The quote for the Weissmann storage combi, the small one with 56 litres, was £5200 and required an £800 power flush. This is probably what I will go with further down the line, rather than a massive standard combi but I’ll try and find someone cheaper as that seems extortionate for a boiler that only costs £2200 from Screwfix.
It’s an old house with dodgy floor joists, I don’t really want a massive cylinder on them, so that’s why I’d considered attaching a 150 litre cylinder to the existing combi. Then I’d replace the existing combi with another small 28kw cheapo Baxi when it breaks.
To be honest the current setup with two cheap Baxis and two supplies has been absolutely fine. It all works and the showers are powerful. I’m struggling to see the benefit of spending big money on top of the range boilers and massive cylinders.
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