NMEA

This epic, arrived at a customers boat at 8 this morning, fitted the heater and left at 4. The rads and plumbing were all installed already though otherwise it would have been three days

You could have saved so much time (and probably money) by just buying the correct narrowboat kit in the first place as it has all you really need.

Its female BSP hosetails you need, they screw onto the 3/4 bspm to 22mm compression fittings.

The pump inlet and coolant outlet are actually 20mm and the Webasto hose supplied with the kits is 20mm bore, it is sufficiently malleable to slip over 22mm tube, however that is not the correct way, you really should be getting a 19mm hosetail fitted to the feed ad return tubes. This is normally done using a 3/4 BSPM to 22mm compression fitting and a 3/4BSPf to 19mm hosetail. Though I usually make the interface at the bulkhead using a similar affair but with flange nuts either side of the bulkhead.

Fully tinned Japanese Y bullets would do you perfectly, corrosion resistant and demountable. They have proper ads cheek crisps for secure strain relief and separate insulating boots. If you Google Y bullet terminals it should bring some up.

Do you mean Piggy back spades, but splices or something else?

3m gelcoat restorer is pretty good stuff but once the Seagull crap has yellowed it not much apart from oxyallic acid brings the white back.

If your filter has 1/4" or 3/8" BSP ports like the ones I use then there is no need to have a flare on the inlet and outlet, simply use a 1/4 or 3/8 BSP to 5mm compression fitting with a plain end on the pipe, don't forget the pump should be as close to the tank as practical, they prefer pushing to pulling fuel.

The end should be formed rather than flared, most flaring tools have the former that makes a smooth bulge rather than a flare.

Do not try to use the standard Webo tank fitting on a tank wall. The likelihood is they it will leak, they are designed for tank tops where they have zero head of fuel. This is why we Webasto dealers that do a lot of narrowboats and widebeams came up with the now tried and tested method being discussed here. I was thinking of making some and putting them on eBay but the time spent would not be worth the price one could get. When you get the fitting it is sometimes necessary to run a drill right through it to allow the pickup tube to pass through.

It's also worth a mention that where you use the rubber joining hoses at the tank, pump and heater (BS 7840 hoses only allowed) that the copper pipe should be formed, it's a BSS requirement. Though I doubt any inspector would dismantle to check I have seen non formed ones pull out and anyway it's another one of those things where you know the job has been done right. A brake pipe flaring tool using the right former is a good enough tool for this, you can also achieve it by using a compression olive and then removing the fitting.

Some people get away with tapping the fuel line and others find it causes issues and poor running or non starts after inactivity due to drain back.. I always use the correct method straight from the tank as it only takes fifteen minutes to drill and tap the tank wall and install a 2mm bore tube using a 1/4 BSP to 3_16" compression fitting, this always works perfectly and continues to do so for ever.

No, the thermotop is programmed to reduce to half rate when the returning coolant reaches a set temperature. Also a faster pulse during start up, the air motor matches the pump rate to ensure a constant fuel air ratio.

The hydraulic resistance is not really a variable and does not affect the pulse rate. Well I guess it might if you tried to pump engine oil instead of diesel.

No the Webasto is a solenoid dosing pump, all evaporator heaters are solenoid dosing pumps, the fuel rate is regulated by the ECU. Earlier heaters had two levels but more modern ones are stepless. As a rider the larger Webasto pressure jet heaters ave an internal high pressure pump but as those are rarely seen on narrowboats it is of not really of relevance to this discussion.

Definitive answer, even Webasto PUMPS give a different dose per pulse dependant on the pump and there are six different models of pump. Even the latest AT EVO PUMPS deliver a different dose than earlier models. This is just another reason why the YouTube videos of a so called service done by amateurs are useless as the datum for any heater service is pump calibration and burn rate.

As I have said previously, nearly all the new installs we have done for some time have been pressurised. It really doesn' matter where the pressure vessel is as the pressure is the same throughout the system. Just put it wherever is easiest, it is worth mounting the pressure gauge where it can be easily seen.

Being marine trained an AAV to me is an air admittance valve, also known as an anti siphon valve The others I have always known as bottle vents or Spirovents. It' Also true to say that if you Google AAV plumbing supplies it will come up with any number of air admittance valves but no bottle vents or Spirovents, I stick by my earlier comment.

The Screwfix own brand central heating antifreeze is what we have used for years in new installs and coolant changes but don't mix 50/50 like for engines, a 25% solution is better for carrying the heat and gives more than adequate protection. Goes under the name of Flomasta.

You cant defy the laws of physics.

IF you had a battery bank the size of a football pitch or are on permanent shore power I guess it would be OK.

Thats exactly what I'm saying, the optimum is around the output of the heater in rads and ignore the calorifier, the calorifier rips therms from the coolant when cold but as the potable water temperature rises it takes less and less and then almost nothing. The rads tend to take a fairly constant level, (unless the air temperature rises to 70+ decrees C ) It will of course work, but not optimally and will coke up faster. Servicing is not the same as a decoke, a decoke is pretty straight forward and I can send you a manual if you PM me an email address. Servicing requirers an exhaust gas analyser, pressure tester, software, pump calibration equipment and a test tank with RdLyme to remove internal scaling.

Its acceptable, but if installed to Webasto protocol with correct loading it should rarely happen, especially if the unit is only run for a couple of hours as recommended.

Because so many installs are inapropriate for the boilers, and its usually the boilers that get blamed for any resulting faults.

All Webasto, Eber and Mikuni boilers are modulating, cycling is when the coolant quantity is so small and the radiator load so small that the unit is not allowed to works as it should which is to heat the water to temperature and then maintain it using half power. If the heat produced on half power is not dissipated by the load the coolant temperature continues to rise and the unit shuts down its burner and continues to circulate the coolant until such time the returning coolant temperature drops to a level where the burner fires up again, and so the cycle begins again. The latest Webasto evaporator boiler due to be released soon (already available in 24VDC) has more steps in the heat output so should go a long way to reducing cyclings in poorly designed systems. Edit to add tat the above applies only to evaporator heaters and not pressure jet boilers.