Spinny

OK I will do some more measurements. I am quite prepared to pay to replace the lead mains pipe. However this will take weeks/months to achieve. Meanwhile this stops internal works progressing because if the mains is upgraded but makes no difference, the MLC pipe will then have to be replaced. The later this occurs the more flooring and finishing will have to be ripped up to achieve it. I am not risking £1000’s on hearsay that the 25mm MLC pipe and its 14mm ID connections will provide 30l/m flow. I need to know now ish if this MLC pipe is an inadequate throttle point as I suspect. (I have already had another plumber advise that the MLC connectors are a real problem and must be replaced. Press fit connectors have been used on the rad pipes downstairs too and all the rads will not heat up. Copper pipe on the rads upstairs and they all heat up fine.)

It isn’t just pressure though it is flow rate. When a tap is turned on the shower flow drops by up to half. The way I am thinking of it the system is like a balloon. If you let water out of it faster than it can flow in then the pressure in the system will drop and you will never get more flow rate out than you have coming in. I can get 20l/m from an outside tap on 15mm copper direct from the mains. But I only get about 12l/m total from outlets downstream of the UVC and MLC pipe. Something is choking off the flow. Back to the straw analogy, all points in the pipe must have the same flow. Yes the velocity will be higher in the straw section. But the question is will the straw section reduce the flow through the pipe. Intuition and practical experience says yes it will, otherwise we wouldn’t have 6-12inch water mains under the road we would have straws. Put a nozzle on a hose pipe and you increase the velocity at the nozzle but you still reduce the flow rate through the pipe.

Not sure that is the right approach though, it is the flow rate through the total pipe length I want to know not just a pressure drop. If you replace a section of a hose pipe with a straw, I rather think it will drastically reduce the flow rate through the hose. Even if the straw is only a few cm long.

It’s gone quiet. Any plumbers going to comment ? How would I calculate the flow through say 4m of 25mm MLC pipe choked down to 14mm diameter at either end ?

So went out today and bought one of the 25mm press fittings the plumber has used to terminate his MLC pipe run between mains and cylinder. It provides a tail to fit onto 22mm copper. The ID of 22mm copper pipe is 20.2mm. That is an internal cross sectional area of 320.5 sqmm. The ID of the press fitting is just 14mm ! That is an internal cross sectional area of just 153.9 sqmm. LESS THAN HALF A 22MM COPPER PIPE! Don’t let your plumber fit this crap.

Does a water softener really reduce pressure by 0.5 to 1 bar ? My mains is 3.5 bar and installing an UVC so this alone would take me below the 3bar the system should run at ?!

They can’t wait to board and skim over things before the customer can say why are there untested pipe joints in my wall, and red bull cans and vapes in my wall cavity. Most customers won’t even have a spirit level.

Ok, but I’m not a complete idiot, I read the ‘5*’ reviews, visited and spoke to 2 other customers, and had multiple pre contract meetings. The reality is many customers wouldn’t have a clue whether their builder is doing things properly or badly. They are out at work or housewives etc with zero building/trades knowledge. Therefore their excellent reviews are in reality worthless. Builders carefully curate their refs and websites, concealing their unhappy customers and bad jobs. In my experience they lie to their customers frequently. Ive already had another builder promise help and then renege before starting. People don’t turn up, gaslight for months over providing a quote, even block your calls. They turn up ‘first thing’ at 9:30 and ‘work late’ until 3pm. No doubt there are good honest builders and tradies out there somewhere. IMO the industry needs major reform to stop the cowboys, incompetents, and ‘get rich quick with a limited company shell’ merchants. And before the victim blaming gets going, I expect some issues, pay my bills, and support in many ways. Rant over. Can you join MLC without using press fit ‘strangulation’ connectors ?

So I have: 1/ Downstairs rads piped with press fit connectors 2/ Upstairs rads piped with copper Two downstairs rads won heat up properly. Impossible to achieve all 4 rads up to temp. Plumber failed to solve by rebalancing twice. On 3rd visit he has tried to con me by turning up the boiler temp to 65 when I wasn’t looking. Upstairs rads now reach 64 and pretty scalding hot. Press fit connectors/pipe clearly restrict flow and are crap. Now a major problem as floors will need to be destructively removed. I also have flow problems on the UVC where the pressure falls from 3bar to 1.4bar when a tap is turned on. This despite supply being 3.5bar and 20l/m. Again supply is linked to cylinder via 25mm MLC pipe and press fit connectors. Again the connectors must be choking off the flow with their restricted bore. Press fit inc MLC pipe is not fit for purpose (perhaps unless oversized). Is there any way to connect this pipe without using press fit restricted bore connectors ?

He has fitted one tundish which is the black one directly above the trap in the photos. Here it is in close up in another pic. Tundish not easy to keep an eye on tucked behind the cylinder when it could have been further forward. Also wondering if there should be 2 separate tundishes, one below each valve so you can see which one has opened ? He has plastic waste pipe below the trap which runs across under the floor into a drain pipe - as per final photo. Is there a way I can tell if the pipe is OK for 95C water ? As I understand some plastic pipe is OK for high temp and some not. It is going to be big problem to put a new pipe under the floor now as it is glued & screwed down with u/floor heating pipe in it !

Any feedback on the last post and photos please ? Is this tundish plumbing compliant to regs and acceptable ? ta

This is what the plumber has done to install the tundish he had failed to install below. Does this meet regs ?

The problem with builders is you don’t know what instructions they dictate to the tradesperson, or on what basis they employ them. I suspect the builder would instruct that no way is he lifting floors or replacing pipe. In other cases I suspect builder is using job and knock etc. Found out too late, Never, ever, ever, employ a builder. Their objectives are to screw maximum profit out for themselves. It isn’t their house so cheap materials, slap dash and hidden bodges are what they want. Every shortcut is more money for them. Cheaper tradespeople make them more money, you still pay the same for shoddy work.

It’s the builders plumber and like most of the builders tradespeople is crap. I am 80 weeks into a 22 week single storey extension build. The problem is if I don’t keep holding the builder accountable for fixing most of his constant screw ups then I end up paying twice over. Still waiting on other plumber quotes and new pipes will mean taking glued & screwed floors up again. I am trapped in a living hell.

He hasn’t done a calculation since he left school. He is bullshitting me about G3, rarely turns up, leaves me with no heating for a whole winter, no sink, no w/machine for 14 months & counting. 2 leaks from his pipework, stole the old copper cylinder and pipes, radiators don’t heat up properly, lousy water flow. Best thing would be to pull his fingernails out and drill holes in his teeth.

FFS Why should I have to do the plumbers job for him ? Why am I paying him ?

Plumber has just left a crimped join end exposed on the plumbing he is doing in my build. Photo attached. Measurements show that the external diameter of the connector is about 14mm and the internal diameter is 12mm (this is a connector on 16mm MLC pipe.) However as can be seen in the photo at the position of the pressed connector the internal bore is severely reduced - down to approximately 6.5mm internal bore. This is making me angry. How can this in any way be equivalent to 15mm copper pipe with an internal bore of around 13.5mm ? It is restricted to 6.5mm at every connection !? How can this be acceptable ?

OK I see. Thanks. I guess that is another possible option - get myself G3 certified and then certify the work the non G3 plumber has done. Id be ok with the theory but I guess there is a practical element or a need to already be a qualified plumber first. So not viable for me.

Why would they inspect if you are G3 and gas safe certified ?

And if they claim their gas safe card hasn’t been updated yet ? As I understand it if you complete and pass a G3 accreditation training course then you are issued with a specific G3 photo ID card. So some plumbers may carry both cards, but others just carry their gas safe card if it has been updated to include their G3 approval. Perhaps someone who has done the course can confirm ?

Well for a gas safe plumber I understand their G3 status gets recorded on the gas safe register. Although when I try to search for plumbers with G3 on the register there don’t seem to be any in my major city ?!? (But perhaps that is just a problem with the gas safe search function?) if a plumber won’t show you a separate G3 accreditation ID card, how do you definitively establish they don’t have G3 ? (other than simply waiting forever for a G3 regs certificate which never comes and never being able to get the build approved by building control as a result) Presumably if reported to gas safe they would get struck off for being a lying **** . But then you would end up with no G3 and no gas safe either.

I don’t see uncertified as an option… - Stops BC signing off the build - Invalidates insurance - An issue if selling the property - unethical & ‘illegal’ why are manufacturers allowed to sell unvented cylinders to non G3 plumbers ? oddly cylinder manufacturers run systems to trigger gas safe and g3 certification when the plumber registers the install/warranty. But surely they should check the plumber for G3 at point of sale, not post install.

Hypothetically, If a plumber installed an unvented cylinder without holding a current G3 certification, how would this need to be resolved to get the unvented cylinder install certified as G3 building regs compliant ? And what would be the warranty situation ?