identifying a system

[g60rge]

got called out to have a look at converting an open vented system to a combi, but for the life of me couldnt work it out, ive done a few before with no probs but this one had me stumped, pretty sure i can work it out once i start taking out the cylinder and boiler but i like to know what system im dealing with to be able to price the job,

Outside we have the boiler in a boiler cupboard with the flow/returns in a wooden box on the outside of the house, (4 pipes comming down, 3 are 22mm one is 15mm all linked into the heating pipes. The pump comes off what i presume is the flow, then into a 2 port valve.

in the cylinder cupboard there is no 3 port valve

so all i can see is one 2 port valve??

any ideas?

 

[lame plumber]

gravity flow to cyl, 22/15 on CH system to pump and valve?

 

[g60rge]

sounds right, off the coil one pipe is 15mm and one is 22mm

yes the 15mm tees in near the valve just after the pump which goes up in 22mm

so the pump is on the return?

whats the other 22mm pipe then?

thanks

 

[lame plumber]

not what i thought at all, so cyl coil has 22 and 15 flow and return, you really want to just go and turn it all on and see whats what, then youll know how it works and what your going to rip out and replace. All you realy want is to know where the flow and return for the rad circuits are, and where the hw flow from the cyl is and have a cw supply. the rest is redundant

 

[g60rge]

damn, i thought you knew lol

top of coil is 22mm
bottom is 15mm - not seen that before

i knw what your saying im good at working it out as i take it out but pipes go through tiled bathroom and hoping i dont have to run another pipe

i may have to partner up on this job

 

[TBServices]

Could be feed and vent direct from boiler, plus f+r. May be that 2 port controls heating but HW is always on. Seen this before.

 

[lame plumber]

agree with tb, but youve got to be sure and correctly id all pipes for new system to work.

 

[gassafe]

I too like to get my head around a system before quoting it! It ensures I'm not going to have any nasty surprises if I get the job!

Customers don't help when you go to look at the old boiler or airing cupboard & its just rammed with clothes & junk... Not a pipe in site half the time!!! And then when I want to see what pipes are where they look at you as if you don't know how to do your job!

I like to know the main bits like where that pesky cyl return has been teed in, and finding the main f & r for rads etc!

 

[g60rge]

i was thinking this when i was looking at it actually, feed right down to the ground level to make filling easier with air locks because downstairs flow and return tee off in the boiler cupboard and back in the house, no other drop in the house i guess..

but didnt understand coil comming off in 15mm, maybe turns into 22 under the floor somewhere

starting to make sense now but will need to check the hot water on constantly thing which also is making sense as customer says the bills are always high.

i appreciate all your help, what is this type of system called?

modified s plan?

 

[gassafe]

I find a lot of customers are either very selfish or just dumb! I mean if I had someone to quote a replacement boiler I would clear the whole space around it etc!

A recent one which annoyed me was a boiler in a garage! The chap said when I arrived "do you need to see the boiler?" The garage had a classic car in it, no room whatsoever to squeeze thru, could not even see the boiler it was just covered head to toe! Could not get car out without moving two further cars off the drive?... I mean come on... Help us out!!!

 

[g60rge]

propper plumbers take their time to work things out first. nothing wrong with that. That bit when your thinking and they think you dont know what your doing. haha

thinking and working things out all part of the job and probably the most important.

 

[TBServices]

I've seen a lot of cylinder returns piped in 15. If it was a perm HW set up, it would promote flow through rads instead of coil leeching all hot.

Tbh bud you just have to quote for worst case scenario.

 

[g60rge]

yeh, it gets capped anyway as well as the flow to the coil, cut out the 15mm feed, id the vent, cut that out too and that leaves my flow and returns

could end up being easier than i thought, but always something bites you in the bum so not discounting anything

 

[g60rge]

yeh, it gets capped anyway as well as the flow to the coil, cut out the 15mm feed, id the vent, cut that out too and that leaves my flow and returns

could end up being easier than i thought, but always something bites you in the bum so not discounting anything

Up to the top

 

[stevetheplumber]

sounds like cold feed and vent and f&r to me gravity hw nearly always in 28mm can you see a feed and vent of the cylinder pipework

 

[g60rge]

yeh think it comes up in the cylinder cupboard and straight into the loft

didnt see any 28mm there

 

[tamz]

It is as Steve said. Fully pumped with the feed and expansion straight of the boiler. Just rip it out and do your thinking while you're working.

 

[dancinplumba]

It is as Steve said. Fully pumped with the feed and expansion straight of the boiler. Just rip it out and do your thinking while you're working.

Life would be a lot easier if they did tamz, fer sure

 

[g60rge]

cheers lads, il update if i get the job although i think its mine anyway

 

[dancinplumba]

It is as Steve said. Fully pumped with the feed and expansion straight of the boiler. Just rip it out and do your thinking while you're working.

Thought it was just in my world till I came on here, Am truly staggered by it's extent

 

[tamz]

Aye yer not kidding Steve :smile:

 

[g60rge]

haha update

went round and had a better look again today (took my time this time), opened the box that housed the pipes

4 pipes
x1 15mm cylinder pumped return (ties in with 15mm bottom of coil)
x1 22mm gravity cylinder flow (ties in with the 22mm top of coil)

x1 15mm ch flow
x1 15mm ch return

so upstairs heating (x5 rads) is all on 15mm pipework!

i guess i gave you all the wrong info on the pipe sizes from the beginning and made you think something else.

learn something new every day, whether it be on the net or on the job!

il have to upgrade to 22mm as far as i can and hope for the best