Combi boiler "Drain Point"?

VoucherMan

I just doing a little tidying & preparing for a bathroom refit, and wanted to identify the route & purpose of a few pipes that will need moving.

I'm reasonably confident on this one, but neither Google nor the instruction manual confirms anything, so hopefully someone here can.

The grey plastic pipe on the right of the picture is, I think, the Boiler Drain Point. The only reference to it is on a diagram (p8 of the manual).

From the state of the outlet pipe (I always wondered why I had 2 'overflow pipes' poking through the bathroom wall) I don't think it's ever been used, so just wanted to confirm it's actual purpose. The name suggests it's for draining the boiler, but not the rest of the system, which is what I've always done.
So unless there's a fault that needs an empty boiler, it's never likely to get used?

Installation & Service Instructions Main Combi 24 HE pdf



Also, where the pipes come out under the bath (boiler is in the attic),the drain pipe (bottom pipe in image below) runs from back to front (under the U-bend) and then to the right, heading out through the wall to the drain. There's a T-joint, with a smaller pipe to the left. This pipe goes nowhere though, and isn't even capped. It's just angled downwards for a few inches, then bent vertically upwards, and severed just below floorboard level. From what I can see, this would be a far more likely route for any water to take if the drain were ever used.:eek:

Everything should be much clearer once the old fittings are stripped out, but I'm a little concerned about this pipe & it's abrupt termination, and wonder if I should point it out to the fitters to properly cap it, just in case the pipe's ever used.:think:

thescouselander

I haven't read the manual but I'd say it's probably the condensate drain. Usually the drain valve for the whole system is on one of the downstairs radiators.

bridgedino

It'll be the pressure relief discharge pipe, it's purpose is to allow the system to self discharge when the pressure reaches 3 bar of pressure. It's a safety discharge point and can't be capped or disconnected

The white plastic pipe is the condensate discharge pipe

molerat

It looks like the pressure relief valve and primary drain down use the same outlet. The thicker pipe coming out of the boiler then straight to a right angle is the condensate drain. They obviously don't use decent tech authors !

edit: too slow looking at the manual.

bridgedino

The drain point for your boiler is a small white wheel valve located inside the boiler case on the right hand side behind the pump

VoucherMan

bridgedino wrote: »

It'll be the pressure relief discharge pipe, it's purpose is to allow the system to self discharge when the pressure reaches 3 bar of pressure. It's a safety discharge point and can't be capped or disconnected

Thanks for the replies.
Another quick question while I'm thinking about it. The manual states:

6.7 Safety Pressure Relief Valve (Fig. 6)


2. The pressure relief discharge pipe should be not less
than 15mm dia, run continuously downward, and
discharge outside the building, preferably over a drain. It
should be routed in such a manner that no hazard
occurs to occupants or causes damage to wiring or
electrical components. The end of the pipe should
terminate facing down and towards the wall.


3. The discharge must not be above a window,
entrance or other public access. Consideration must be
given to the possibility that boiling water/steam could
discharge from the pipe.

The pipe exits through the bathroom wall, facing away. It's directly above my cellar door.

While I appreciate the safety aspect of this, the chances of the pipe being used at the same time as someone being under the outlet are so small that I'm quite happy taking the risk, especially since the pipe run from the boiler to the outlet is long enough for the water temperature to hopefully drop to a safe temperature.

Knowing how regulated the industry is though, are there any rules about the location of the pipe, or is it purely recommendations?
Along with the bathroom work I may be having some external pipework moved, so it would be a good time to fix the discharge pipe, make it fit for the next boiler (hopefully not replacing that for 10 or 20 years, but still wouldn't fancy ripping up the bathroom floor later)

southcoastrgi

The grey plastic pipe on the right isn't a drain & shouldn't be used as one, it's the safety pipe & should really be in copper but looking at the state of the rest of the plumbing under your boiler I'm not surprised it's in plastic

adonis

southcoastrgi wrote: »

The grey plastic pipe on the right isn't a drain & shouldn't be used as one, it's the safety pipe & should really be in copper but looking at the state of the rest of the plumbing under your boiler I'm not surprised it's in plastic

I think the installer must have mislaid his spirit level that day.:rotfl: