Is my boiler / tank working properly?

[DavidAUK]

I recently had central heating installed. A Megaflo tank and a Vaillant Ecoplus 630 boiler. The house is warm and I have hot water, so there is no emergency. I have nagging feeling it's not working 100%.

1. The pressure seems low. It's at 1.7 bar. I had to bleed the towel rail (for the second time) which has brought it down. The needle shows the pressure at minimum and I'd like to increase it, but the manual doesn't tell me how. I thought there'd be a tap to turn on like on my old combi boiler.

2. It takes a while for the taps to get warm. I hoped that we'd have hot water on tap but I have to let it run for about 15 seconds. I guess the pipes that serve the taps could cool down, but I can't think why the water in the hot tap would be lower than room temperature. Am I missing something?

I find the manual to the boiler confusing and the manual for the tank very confusing. Can someone here explain it to me like I'm five?

 

[John506]

I think the 603 has a filling loop but already built in. If you can get your head under the boiler there will be a pipe connecting from the cold into the flow/return, and you use the quarter turn isolation valves on the boiler jig itself to fill the heating.

 

[MeldrewsMate]

Firstly a system pressure of 1.7 bar seems a little HIGH, not low. Normally the pressure ranges between 0.5 bar and 2 bar, dependant upon the installation. A higher pressure gives no advantage over one which is adequate.
Your installer should have explained the setting he left it at, and the method for topping it up. Were you listening?
having to bleed air from the towel rad in the first few weeks is not unusual, however the quantity or air removed should rapidly diminish on each bleed. There is the possibility that internal corrosion is occuring if it continues; speak to your installer about how he cleaned the system, and what corrosion inhibitor was used in the system water.

Secondly the hot water, unsurprisingly, goes cold in the pipes over time. The hot water, generated in the Megaflow, takes time to travel to each hot tap, and that time is determined by the distance it has to go, and its velocity on the way (no 5 y/o explanation available). So 10 metres of 22mm pipe will have an internal volume of about 3 litres. Clearly you must throw 3 litres down the plughole before the hot starts to come out of the tap.

The solution may be to explore hot water pipework routing that keeps the pipework internal volume to a minimum, by reducing the pipework length and or its diameter where appropriate.
Another solution may be to install a secondary hot water circulation loop; see your installer for details on how this can be achieved.
And finally you can keep the hot water warmer for longer in the pipework by insulating it!