gas pipe size and combi boiler failures.

roddydogs

? dripping tap.

heating-eng

roddydogs wrote: »

? dripping tap.

No. The weather was just so bad.
My mate went to a condensate that was 6m long vertical (50 mm pipe ) that had frozen. Frozen from the bottom all the way up to the boiler.
Remember the weather was extreme and we are not going to get it like that very often.

roddydogs

Can only assume that the temp inside was below freezing (where the u-bend is)

Pincher

It's a domino effect disaster movie.

Let's see. They left for a week's winter holiday. The bath tap was dripping.

Obviously they left the boiler on so frost protection will come on, which it did. The boiler kept working until the condensate froze and blocked the pipe, and killed the boiler. The house starts plunging down to minus 10 degrees. Ice builds up from the dripping in the bath waste, which freezes and blocks the bath. Dripping continues so the bath fills a bit more, until finally the dripping stops because the whole house is arctic. The bath now proceeds to freeze as well.

Isn't this what happened to Narnia? Hundred years of winter, but never Christmas.

heating-eng

roddydogs wrote: »

Can only assume that the temp inside was below freezing (where the u-bend is)

The pipe had frozen outside. Not inside, the boiler worked fine as it was not a condensing boiler (lol)
Maybe some of you guys are down south and don,t really get the cold weather as much as we do up north.

lemontart

Pincher wrote: »

Had to buy a 1 meter masonry drill bit myself, because my builder won't buy one, and couldn't find someone to "borrow" from after a week. And then the plumber won't do it with the drill bit because he won't be responsible. So I had to do a diagonal hole at 15 degrees slope myself: success on second attempt.



In one house, I have a floor standing boiler, it comes with the condensate pump, and I don't think I can avoid using it.



Hear, hear. Combis bad.

For those with no space for a cylinder, there are gas water heaters, which are sadly out of fashion because housholders think combis are cheaper and more compact. They are right, until the damned thing breaks down, and it seems nobody can diagnose the fault because it's too complicated.

Rinnai do externally mounted water heaters and boilers, taking up ZERO internal space. You might as well run the gas pipe externally, which is safer any way.

]#

i have had a ch boiler and a seperate water heater for years and would not dream of having a combi given the level of reports I hear of them not doing the job for one reason or another

heating-eng

lemontart wrote: »

]#

i have had a ch boiler and a seperate water heater for years and would not dream of having a combi given the level of reports I hear of them not doing the job for one reason or another

A combi boiler is much better than what you have. If fitted correctly in my opinion.

kleftiko873

winter looming suffered 2 previous winters of boiler shut downs due condensate freezing, tried everything to stop it but nothing worked. 'which' magazine (november 2011 issue) says trace heating must be installed by gas safe engineer yet advice from worcester bosch to me was to buy and fit trace heating to overcome my problem, they suggested i buy trace from DIY store. if this is their advice it should form part of the installation instructions/training to the heating eng. my run was outside about 4 mtrs. trace was installed by changing the 32m pipe to a 22mm this allowed for thickness of lagging and cover pipe. the 22mm plastic pipe was wrapped in aluminium tape then trace heat cable was tye-wrapped to underside of pipe. pipe then lagged and a standard 3" plastic cover pipe (drain pipe) fitted over the whole system to keep it dry, finally trace warning labels fitted. waiting for the big freeze to see if it works. before starting i plugged the trace cable into mains supply and held cable to feel warmth coming thru, its a very gentle warmth. the cost is about the same as running a 50watt light bulb. the installation was not difficult and anyway couldnt find a local heating eng. who could/would do this work so hobsons choice. will advise results.
pete

19681

A self regulating heating system is used as a solution due to its ease of installation, safety and lowest running cost. Kits are designed specifically for frost protection of pipework in the domestic / residential sector, especially boiler condensate dischrge lines.

The last two winters have really given a new meaning to the prevention of frozen pipes. Each year most industrial and commercial buildings generally take precautions to protect exposed pipework, but with unpredictable winters it has opened up a domestic market with a real need for frozen pipe prevention.

Key engineering features to look for in your pipe frost protection kit are very important and some of these are listed below:

1) The In-Line thermostat must be fully weatherproof and rated IP67 - it should operate by sensing air temperature and not by sensing at a single position on the pipe itself, thereby ensuring maximum protection is achieved at all times.
2) Assuming the maximum pipe size to be 32mm, the kit must provide frost protection at the lowest temperatures recorded during Winter 2010 – Look for self regulating rated at 12 w/m @ 10ºC and the recommendation to install in a straight run on the pipe and then install a minimum 13mm thickness of thermal insulation after fitting the trace heating. The heat loss calculation should be based on IEC 62395, the Standard for Electrical Resistance Trace Heating Systems for Industrial and Commercial applications
3) The flexibility of the heating cable must assist the installer, simplifying handling on site and providing ease of installation – this is particularly important when the installer has to fit the self regulating cable in a loop on the pipe within the wall
4) The small cross section (geometry) of the self regulating heating cable should allow the thermal insulation to fit comfortably and keep the aesthetics of the installation to a good standard and acceptable to the property owner.
5) The kit must include a spare end cap to enable the length of self regulating heating cable to be cut to the exact length of the pipe and sealed
6) In-line junction box in the kit must be complete with cable retention clamps to EN-60598-1 & BS4533 for increased safety

Hope the above helps

SYNERGY

roddydogs wrote: »

"Very popular"? you cant fit any other!
Op should try this..........Turn Boiler off, put ALL the gas cooker on full, inc all hobs, set CH boiler to on (boiler firing) and watch the hobs to see if they fluctuate., if they do its the pipe size.

A rare cause of low or fluctuating gas pressure can be water in the company main at street level, not as frequent now, with the plastic pipes, as it was with the old cast iron, but it still happens :eek:

It can take ages to find, the pressure can appear to be OK, it is the volume that's the problem.

Difficult to spot, one clue is that of several complaints on a street of fluctuating, or low pressure at times of peak demand, with say 3" of water in a 6" main, effectively reducing the bore by 50%, it's no surprise.

Complaints appear to be taken individually, the gas suppliers complaints systems appears not to be able to recognise several similar complaints on one street.

The fault is recognised, usually, by an old school fitter being called to several properties in the same street and recognising that the fault affects the street.