2 Plumbers 2 Different Views 2 Different Quotes _ Help Plea

[s2sap]

Hi Guys

We have been having probs with central Heating in that the hot water does not seem to be pumping far enough round the system ie its very slow. Both plumbers agree that it is a pumping issue. One recommends a light commercial pump outside at the boiler cost installed £300. Second plumber says no need for that expense put a second pump inside the house before the first tee as the run from the garage to house is too far and the second pump will push the water round the CH in the house and first pump will get it from garage to house - cost £45 for pump plus £140 for installation. I dont mind paying for the right thing but dont know what might be best - anyone any experience of this. There are 26 radiators - it is a large house and we have a Wilo 60 pump already installed at the boiler - plumber recommending second pump says he will fit Wilo Smart Pump - not sure what first plumber is planning for the light commercial route

 

[glasgowgas]

whats your boiler output in kilowatts?

 

[oilman]

Has it ever worked properly? If it has there is a fault which will not be dealt with by putting another pump in, unless it happens the present pump is faulty. Scale will not be your problem in Aberdeen (or anywhere else in Scotland I suspect).

 

[Agile]

Just because the water supply is soft does not mean that the system cannot get dirty with oxides etc.

Tony

 

[D_Hailsham]

I wonder if the pump was properly sized? With 26 rads it would need to be; the same goes for sizing the pipes and calculating the index circuit.

I can't see any point in "taking a suck it" and see approach, which is what both plumbers are doing. Installing a second pump fed from a low loss header might be a solution.

[code:1]
Header
---------- Pump ___
| |====O====| | Pump
| | | |======O=======To Rads
| Boiler | | |==============
|_ __ _ _|=========|__|
[/code:1]

 

[kevplumb]

I wonder if the pump was properly sized? With 26 rads it would need to be; the same goes for sizing the pipes and calculating the index circuit.

I can't see any point in "taking a suck it" and see approach, which is what both plumbers are doing. Installing a second pump fed from a low loss header might be a solution.

[code:1]
Header
---------- Pump ___
| |====O====| | Pump
| | | |======O=======To Rads
| Boiler | | |==============
|_ __ _ _|=========|__|
[/code:1]

how is it going to help

 

[D_Hailsham]

Installing a second pump fed from a low loss header might be a solution.

how is it going to help

It isolates the circulation of water through the boiler from that through the radiators, so the pump feeding the radiator can be smaller. The existing pump will be OK for the boiler circuit and can probably be turned down to minimum.

 

[kevplumb]

yeah right

might make a difference on 3 zones with 21 rads each

and two boilers and shunt pumps

 

[s2sap]

I will try and give you the info you are asking but firstly the system was installed new in a house that we bought from a private builder 3 yrs ago – no comeback there. The problem has been like this since inception. There are 3 circuits upstairs ( 6 rads ) d/stairs (20 rads) and water all work independently. System is sealed system

Boiler is Warmflow Bluebird 1215 max output 44KW max BTU 150,000

Pipes are standard 28mm right through from boiler which is 18metres from the first Tee inside the house which is where the 3 zones start

 

[Norcon]

Oh dear. Undersized pipework!
I'd go with you're first plumber's suggestion.
Just be thankfull you don't have UFH installed.

 

[glasgowgas]

pump undersized, wilo 60 or grundfoss 15/60 cannot cope with 44 kw

up pump to grundfoss 25/80 and you will be on the right path

had similar prob, up in Strathtay, garage about 12 metres from main house 45 kw boiler trying to feed 19 rads and unvented cylinder from a grundfoss 15/60

would not heat all rads on CH only

popped in a 25/80 and it was all roasty toasty

and didnt even balance down rads

 

[s2sap]

pump undersized, wilo 60 or grundfoss 15/60 cannot cope with 44 kw

up pump to grundfoss 25/80 and you will be on the right path

had similar prob, up in Strathtay, garage about 12 metres from main house 45 kw boiler trying to feed 19 rads and unvented cylinder from a grundfoss 15/60

would not heat all rads on CH only

popped in a 25/80 and it was all roasty toasty

and didnt even balance down rads

Thanks glasgowgas

So you would go with the ONE big pump idea as opposed to the second smaller pump inside the house ?
By the way got the price of the quote wrong from first plumber it was £380 not £300 - Again I dont mind paying for a job to be RIGHT but too many times I have been later told that what I paid for wasnt the right thing to do

 

[bengasman]

...Boiler is Warmflow Bluebird 1215 max output 44KW max BTU 150,000...

Should that not have been a band a or b boiler if it is only 3 years old?
Do the rads of each zone get hot properly when you run the zones one at a time?
The fact that the installer designed an open vent system in the year 2006, is not very promising unfortunately.

 

[glasgowgas]

it really isnt that much of a big pump, i usually pay appox £140 for `em

but it has a much larger delivery

not commenting on yer quote, we all have to make a living

the second pump idea is a cowboys pipe dream

a. it would need to be wired in series with CH demand

b. at worst it would be a restriction in pipework

go with yer first mans plan, he knows what he`s talking about

 

[s2sap]

...Boiler is Warmflow Bluebird 1215 max output 44KW max BTU 150,000...

Should that not have been a band a or b boiler if it is only 3 years old?
Do the rads of each zone get hot properly when you run the zones one at a time?
The fact that the installer designed an open vent system in the year 2006, is not very promising unfortunately.

bengasman - I have discovered I live in "the house that jack built" but I have to live with it and make the necessary changes so probably the whole thing is wrong but I need to try and fix it. If I put on the upstairs circuit only ( 6 rads ) it is still slow but gets there eventually. When the system gets up to speed say after 1 hour all the rads are very hot it just takes forever

glasgowgas - is that pump your recommending big enough or if I am going to pay out now should I spend a few pounds more or will that be "too much pump"

Sorry for all the questions but as I have said I am pumping serious money into fixing incorrect work done previously ( not just in plumbing ) and need to know that this money is being spent helping to improve the situation not just going into another bad job.