Boliers and water pressure

[Ian_P]

Hello All,

My Worcester Bosch 240 boiler is currently hanging off the wall and after many years of reliable service is going to the boiler graveyard. My plumber has recommended that I go for a Glow-Worm 38 CXi on the basis that we have a 5 bed/2 shower house. The only problem is that we never use both showers because if one (on the 2nd level) is running you simply don't get the water pressure in the other (on the 3rd level) - in fact you don't get any water from it all.

I have checked the water flow in the rooms and the following is the amount of water in 20 seconds:
Downstairs sink: Cold 3.3L; Hot 2.5L
2nd level bathroom sink: Cold 4L; Hot 2.7L
2nd level bathroom bath: Cold 4.75L; Hot 2.8L
2nd level bathroom shower: Cold 3.5L; Hot 2.3L
3rd level sink: Cold 3.3L; Hot 2.3L
3rd level shower: 3.5L; Hot 2.3L


So, I am wondering whether or not it is worth getting the 38CXi boiler given that we don't use both showers simultaneously. Clearly it would be preferable to use both showers but given that we don't should I just go for the 30CXi?

One thing I'm not clear on is whether a boiler can close the gap between the cold flow rate and hot. I know a boiler won't pump water but does it regulate the amount coming out to ensure it's sufficiently heated so if I go for the 38CXi will I get more hot water in the 3rd floor?

Finally I've been quoted £1400 for the 30CXi and £1700 for the 38CXi supplied and fitted? Reasonable?

Sorry, one final point, we do have a lead pipe coming in to the house with an old tap on it. I know this won't be helping but is there anything I could consider that would increase the water pressure without costing too much?

Thanks

Ian

 

[OLLIE20]

If you have poor pressure coming into the house, you can fit any boiler you like it wont help, you can only get out what you put in, if pressures ****e coming into boiler, its gonna be ****e coming out, you need to sort out the mains supply by the sounds of it

 

[Ian_P]

At those flow rates is my water pressure s**te (to use your technical term)?

 

[fazedup71]

yes your flow rates are utter sheet, you would be best with a cylinder!

 

[gasbanni]

It all depends on the space youve got and what you want to achieve and of course your budget, you could install a buffer tank and pump and have greatly increased flow rates, but then you'd need to consider the hot water requirements and the best way to achieve it. or wether your easonably happy with what you have now, In which case the price quoted seems cheap enough !

 

[mysteryman]

I sometimes despair at the language I see on here!

Your flowrates are not good. Your cold water main has to be able to supply all the water the combi can heat, plus any simultaneous cold water usage, all at enough pressure to reach the top of the house. A 35kW combi might perhaps supply two showers simultaneously if they are proper combi-compatible showers.

You need to consider a cold main replacement all the way in from the company stoptap in the street.

Othertwise, you will need some cold storage [and/or hot storage] or an accumulator. Or a storage combi.

 

[bengasman]

It's not your pressure that is flawed, but your flow is shit; the lead pipe most likely being the culprit.
Check the credentials of the chap who recommended glowworm; not all, but a lot of glowworm admirers don't deliver top quality.

 

[Ian_P]

It has been suggested that I use a company called Flowtec (I think) who will run a new pipe from the street mains in to the house. The distance between these points is only about 4 or 5 metres so it seems quite an easy thing to do.

I would prefer to know if this will work before shelling out any money. Is it possible to check the mains pressure (I think the water company will do this from what I've been told)? And can I then check the pressure in the house?