How To Locate Flow and Return Pipes

The Basics:

Over the years one of the more frequent questions that homeowners ask me is how to locate which of their radiator pipes is the flow pipe and which is the return pipe. The question usually revolves around the need to install TVRs (Thermostatic Radiator Valve) at each radiator. In most cases TVRs are unidirectional. In other words it doesn’t matter if the valve installed on the flow or the return side of the central heating circuit.

When you search for a new valve make sure that you can install on the flow or return side of the circuit. If however you need, or just want to locate the flow and return side it is very easy.

Make sure the heating and hot water system is turned off and all the pipes in the house are cold. With all pipes cold switch the heating system on. Make sure to lease the hot water circuit off if you are able to do so. Some systems require the hot water to be on in order to have heating. As soon as the heating is turned on start checking the pipe work nearest the boiler for the pipe that heats up first. That should be the flow pipe. The flow pipe is the one with the pump attached to it. Start working your way around the radiators in the house and check to see which pipe heats up first. That too will be the flow pipe. Mark the flow pipes with the letter ‘F’ and you will evetually have all the flow pipes marked.

Depending on the type of TRVs you buy you will now be able to install them on the flow side or on either side as you will know which direction the water is flowing through the system.

A very boring subject indeed so if you’ve made it this far congratualtions and good luck.

DANGER OF THE WEEK AWARD

Bad DIY

I offer this piece of advice for all those who have a friend, work collegue, mate, uncle or cousin who loves to dish out DIY advice with no actual training in the field. DO NOT blindly take that advice without using a bit of common sense. Case in point!

We found this serious fault a few weeks ago when asked to repair an apparent burnt out bulb in a bathroom we had fit about a year earlier. When we entered the loft space to change the transformer we found the burnt piece of plastic pipe waste pipe as shown in the photo. The plastic pipe was resting DIRECTLY ON TOP of the halogen light!

A halogen bulb creates a temperature of approximately 250 degrees Celsius (482 degrees Fahrenheit). So why would it ever make sense to place a chunk of plastic directly on to of the glass bulb? Well here is the story as I understood it.

Someone at the home owners place of employment had told them that if they put fiberglass insulation directly over the lamps in the loft that the bulbs would burn out quickly. So a suggestion was made to put pieces of pipe over the ligts to keep the insulation above the light and allow ventillation. The problem with this solution however is dagerous in so many ways.

The biggest issue as can be seen in the photo is that the lamp melts the plastic with the real possibility of causing a fire! Because the lamps have been modified from the original, tested and safe configuration the home woner is now fully resposible for any damages caused. As the modification would be deemed unsafe the house insurance and contents insurance would probably be void. The home wone would also be liable for damages to any connecting properties damaged.

So you could be living in a cardboard box, your home and contents burned to cinders, your insurance won’t pay out, your neighbour sues you for damages and of course the bank wants their mortgage payments every month on a property you can’t live in or sell. All of this because some dope at work suggested a piece of flammable plastic be placed on your hot lightbulb.

As a professional before playing with your electrics or gas! Don’t rely on bad advice that could leave you homeless or worse - DEAD!

DANGER OF THE WEEK AWARD

Cowboy Heating Engineers

Always ISOLATE before you INVESTIGATE. Why? As shown in this weeks photo the heating engineer decided that running 240 volt down an earth cable was acceptable. What’s that mean to you?

The other end of this cable was terminted about a half metre away. This ’shocking’ hookup was down to lazzines and the engineer didn’t care if the next person along got zapped!

Fortunately, the next person along was us. Unfortunately, a lot of home owners have only basic knowledge and might have assumed incorrectly that the green/yellow cable was earth. In this case it was live, VERY LIVE!

The general rule is to isolate before we investigate. I like that! ISOLATE before you INVESTIGATE. When troubleshooting however we will leave the circuit energised while checking voltages as certain points in the circuit.  What we originally saw was the other end of this earth wire connected in a poorly wired junction  box and noticed it was hooked to a live feed from the central heating controls. When we followed it back to the cylinder thermostat we found the problem shown above. In case you missed it, the centre wire (green/yellow) is hooked to a live connector.

The tank thermostat is used to open and close the heating circuit. In general terms, all of the wires on the therostat will eventually be carrying 240 volts through them. There should have been three wires and an earth in order to comply with the building regulations and wire it safely.

NEVER use an earth to carry voltage. No excuses. Never do it! And NEVER assume that a circuit is wired safely. ISOLATE before you INVESTIGATE!

DANGER OF THE WEEK AWARD

Cowboy Electrician

We were re-adding two double sockets to a bedroom which had been removed when some walls were recently rearranged.  When we pulled up the floor boards we found signs of faulty electrics left over by the last person to touch the electrics.

As always with these problems that we uncover I am amazed at how much extra work it takes to do something wrong than to do it right! As you can see on the photo above the wiring blocks, wrapped in black tape, and then cut into the beams - but not deep enough! When the floor boards go back down they actually touch the top of the connector block. Unbeleivable!

So the question that begs to be asked is why wouldn’t the blocks be connected to one side of the beam or the other? It would have meant adding less than a half a metre of cable and an extra couple of connector blocks. As always, the job is done poorly due to about £.50 worth of missing parts.

Date: Aug 2008

Description: After British Gas broke used some interesting sales techniques to a lifelong client the jig was up. Our new client received our name from an acquaintance whom we’ve worked for in the past and we stopped by to see if we could help.

We worked out a strategy for relocating the new boiler from the wet room and created a new location in the loft. After kitting out the loft and checking gas, water and electrics for suitability and safety issues we got on with the job. We completed the work in a couple of days.

Even with the loft conversion and a few minor electrical repairs which needed sorting, which British Gas had not included in their quote, we came in well under their quoted price.

DANGER OF THE WEEK AWARD

Cowboy Gas Fitters

While working on a house next door I spotted this masterpiece of crappy plumbing. Back in 1970 this would have sold as modern art! So for fun let’s follow the flow of water from this condensing boiler through to the main waste pipe.

Condensing boiler, as a by-product of squeezing extra heat from the same volume of gas that would be wasted in a ‘normal’ boiler produce condensation within the boiler. Some of that moisture can be seen in the pluming (the long trail of what looks like steam coming from the flue) and some of the moisture trickles back into the boiler and must be removed or the boiler would drown in it’s own waste!

The waste is gathered in various ways depending on the manufacturer but in most cases flows down into the boiler and out through a 21.5mm overflow pipe. The rules how to pipe up condensation pipe work are well  published so there should be no misconception as to how to do it. In the case of our Cowboy Of The Week Award winner several issues can be seen without having to look closely.

1. The 21.5 condensate pipe is too small for running outside and may cause the condensate to freeze on a cold day, thus blocking the pipe work, thus causing the condensate waste to back up, thus causing the the boiler to shut itself off when the sensor trips, or cause the flooring and walls to get wet when the pipe work leaks.
2. Not enough clips (only one actually!) on the 32mm waste pipe to keep it from bowing in the middle which will cause the water to settle in to the low area between to high areas very much like a lake. The added weight of the water will also cause the pipe to bow even more thus causing further problems such as leaks or the push fit pipes pulling completely out of the fittings. The clips in this case should be spaced out to one per metre of pipe work.
3. The angle of the pipe work should be set using the 90/25 rule. That’s 25mm of fall per 90mm of horizontal run. That’s the building regulation view on the subject.
4. As the pretzeled pipe wraps around the house the pipe work then starts it’s uphill run of about eight inches to end up dribbling down the side of the wall because the pipe didn’t actually run into the trough any more.

So the water flows from the boiler to the outside of the house into unclipped push fit 21.5mm waste pipe with TWO elbows, dribbles loosely into a 32mm elbow which then runs approximately 16 inches downhill from start to finish through an unclipped waste pipe which has bent under its own weight, the flow then turns 90 degrees and flows UPHILL about 8 inches and then dribbles down the wall.

WOW! The safe bet here is that this boiler was installed by a non-CORGI registered cowboy or home owner or a mate who also did the same type of quality work on the electrics and gas as well. Scary!

DANGER OF THE WEEK AWARD

Cowboy Builders

We were called in to remove a redundant worktop unit and sink in a day care centre. After isolating the water we started to dismantle the entire system. We found that the entire worktop base unit was basically being held in place by no less than ONE nail on each side and then almost a tube, or perhaps two tubes of silicone.

There was lots more holding everything in situ but we found this shot the most amusing.

DANGER OF THE WEEK AWARD

Cowboy Plumbers

For the uninitiated, un-vented cylinders like the one pictured above are like pressure cookers. They are usually found in small offices such as the one above to supply hot water to bathroom or kitchen basins. Unfortunately, being under pressure they could explode if not for a safety valve located on the top of the unit. But what happens if the Pressure Relief Valve pops open with someone standing nearby?

If the unit is not piped up properly then the answer is that scalding hot water will spray at wherever the valve is pointed. The one above is shoulder height and pointed directly at a wall which will deflect the water back into someone’s face. I have seen several others over the last year that were pointed directly into areas where bystanders would mulling around.

The rules around un-vented cylinders are set in stone. You must be registered to install them and they must be installed to a published standard and not haphazardly. As cylinders get older and parts wear out or go faulty the risk of serious problem happening increases.

Beware and be safe. Have your older cylinders checked out or replace them with a new unit and have it installed correctly with the Pressure Relief Valve piped so that if it blows the scalding hot water will be removed to a safe area.

If your public use bathroom or kitchen has an unvented cylinder that goes wrong and a customer or staff member gets scalded or worse then scalding will not be the only problem you have to worry about. Liability, liability, liability!

DANGER OF THE WEEK AWARD

Cowboy Plumbers

The answer is plumbing junk! When we were called to sort out a leaking and moving shower the poor workmanship didn’t end with just ill fitting doors and a poorly installed shower tray. The entire unit was poorly installed at every level.

When asked if we could sort out a leaking shower we went over to take a look. We were surprised to find that not only did the shower leak but the doors were installed incorrectly, the door frame didn’t match the tray (it was slightly too long for the tray) and the entire base moved freely when weight was applied inside. When we removed the shower we found the elephant trunk or the absolute cheapest crappy thin walled flexible waste connector we have ever seen. The flexible connector was then compression fit to a solvent weld elbow which in turn was installed into the main waste pipe.

We had originally planned to remove and reinstall the shower but the entire unit was of such poor quality that we suggested an entire replacement. We obtained and installed a quality base unit and door kit from one of our trusted suppliers - Clifton Trade Bathrooms. The home owner is now happy, leak free and the only moving and shaking he does is at the office as the shower base is installed correctly. Exactly the way it should have been in the first place.

Don’t spend your money twice. You cannot have an entire shower suite supplied and fit for a couple of hundred pounds. Pay for quality. Pay for workmanship. You will save money in the long run.

Date: Aug 2008

Description: Our client asked us to remove an old low level ceramic sink unit and replace it with something that was easier for the staff to use. We installed a new unit with a stainless steel sink and matching mono tap. A much more appealing look and the staff don’t have to hunch over to use the sink.