The kitchen tap is to be replaced, the small hot-water cylinder under the sink will remain. You like a model with a pull-out spray in the shop. Before you decide on spout height and finish, another question must be answered: Does this exact tap match this exact hot-water system?
Undersink does not yet describe a connection type
STIEBEL ELTRON explains in its guide that “Untertisch” initially denotes the mounting position. The manufacturer distinguishes between non-pressurised and pressurised small cylinders; non-pressurised cylinders require a suitable low-pressure tap. [ARM] The terms are therefore not merely style variants of a kitchen fitting.
Our editorial recommendation: Start with the unambiguous device identification. Search for existing documentation and the exact model designation, as far as it is accessible without interference. A photo of the closed unit and any existing records can support the enquiry. Do not open any connections and do not infer installation approval from a visible number of hoses.
If it is unclear which device is actually present or whether the installation has been altered, this uncertainty belongs before the purchase. A vague indication such as “small boiler, presumably standard” is insufficient for selection.
Prepare a wish and a technical confirmation
Describe to the specialist company or the technically responsible adviser the desired function: for example more space for tall pots, a different control lever or a pull-out spout. At the same time ask for confirmation whether the specific combination of the existing device and the desired tap is intended and suitable. The decisive factors are the documentation of the products actually involved and the existing installation.
When asking about an alternative, request its exact designation. “Low-pressure version available” is only a useful answer once it is clear which orderable variant is meant. Keep the product identification together with the quotation and later documents. Our recommendation is to place a binding order for a specific shape only after this clarification.
The hypothetical case of a premature order
A family initially looks only for a high black tap. A visually matching model is in the shopping basket; the old undersink unit was not mentioned. Before ordering they send the company the device designation and the product link. The technical check is now to clarify which version fits. The result may also be that a different tap or a newly planned hot-water solution is required.
The family can then compare the tested solutions. They do not have to have an already purchased tap adapted with an improvised conversion to make it fit.
Consider the replacement as a coherent service
Have the order state clearly which existing components will remain, which will be replaced and which tests or commissioning steps will be carried out by the specialist company. Additional wishes should be agreed in advance as part of this coordination. This article describes purchase preparation; it does not provide a connection sequence, pressure test or permission for work on water and electricity.